Bruno Bucciarati's most important character traits are his righteousness and his natural kindness. Bucciarati is dedicated to take the most honorable course of action, even if he puts his life at risk. For instance, at the age of seven, Bucciarati chose to stay with his father when his parents divorced as he thought he should support the one parent who suffered from this separation. Moreover, Bucciarati overtly rebelled against Diavolo when the Boss clearly wanted to kill his daughter Trish Una, resulting in his premature death. Bucciarati is loyal to the civilians of his territory, being considerate with them accepting their requests for help, and is generally nice to the people he meets.[5][6]

Bucciarati respects and upholds several values such as resolve, commending Giorno's resolve in their fight, selflessness as he is prepared to sacrifice himself for his beliefs and his duties, and family loyalty, being outraged that Diavolo would dare hurt his own child. Like his team, Bruno believes that resolve involves to risk one's own life for a just cause, a standard he constantly holds up to by putting himself in danger and betting on the enemy's lesser resolve to prevail, until his climactic self-sacrifice against Diavolo. During their first fight, Diavolo even praised how Bucciarati kept his consciousness and tried to counterattack despite an open chest wound. He also readily admires this same resolve whenever it shows up in opponent, noting that Giorno and Pesci (temporarily) have such resolve. According to Giorno, Bucciarati believes in individual freedoms, and that people are free to die however they wish.[7]

However, Bucciarati also particularly despises the drug trade, which caused his father's death[5] and is hurting the population on a large scale, especially children, thus any mention of it unnerves him. Because of his allegiance to Passione which is selling drugs in the street, Bucciarati is conflicted between his code and his duty as a gang member. Giorno notes that Bucciarati was at odds with himself when he used Sticky Fingers to hide inside the body of a teenager who was addicted to drugs.[8] Due to this, he decided to quietly support Giorno Giovanna's infiltration of the gang while still working for the organization.[9] Shown to be against Narancia joining the gang, telling him to live a normal life, Bucciarati doesn't hold the gangster life in high regard.[10] Bruno also looks down on spiteful violence, going back on his praise of Pesci when he saw that Pesci wanted to kill Bruno's team out of spite rather than tactical insight.

In contrast to his righteousness, Bucciarati has a violent and ruthless side. At the age of ten, Bucciarati murdered his father's would-be aggressors in cold blood,[11] and as a gangster, kept his tendency toward violence. Upon their first meeting, Bucciarati violently beat down Giorno and referred to his interrogation as a torture session[3] and didn't stop the team from beating and torturing Mario Zucchero. Having worked for a gang for years, Bucciarati is an experienced fighter, being able to discern whenever killing intent is genuine, is unfazed by empty threats, and is able to keep calm even during a desperate looking fight. Likewise, Bucciarati will often use lethal force against his enemies as demonstrated against Prosciutoo and Pesci whom he caused to be run over by a train and dismembered, as well as against Secco whom he deafened with a popped car tire.

During a fight, Bucciarati is both brave and cautious. While he is ready to sacrifice himself in order to win,[12] Bucciarati will try tactical retreats and sneak attacks regularly, as seen when he tried to ambush Diavolo. The versatile Sticky Fingers notably allows him to perform unpredictable tricks such as giving himself greater range, or suddenly disappear and maneuver out of trouble. Even when pitted against a physically weaker Stand, Bruno takes precautions and thus he can be seen performing a strategic retreat against Gold Experience and Oasis alike. Nonetheless when push comes to shove, Bruno will recklessly risk his life if it enables him to win following his philosophy of resolve.

Bucciarati is consistently shown to be serious, even as a young child, and usually keeps a serious and unflinching demeanor throughout the story. Moreover, Bruno takes his responsability as a team leader seriously, considering that a lieutenant's has the double duties to accomplish the mission but also to ensure that his subordinates live. That makes Bruno extremely determined in a fight if the lives of his teammates are in stakes, and Bruno routinely takes reckless actions to ensure their safety, for instance dragging Prosciutto out of a speeding train to take him out and prevent him from aging the team to death. During most of the story, Bucciarati always acts with a given objective in mind (take Polpo's treasure or bodyguarding Trish for instance), and always pays mind to it. As a result, Bucciarati can be seen seen reining in his less disciplined subordinates[13] in regard to focusing on their goal. For the sake of his teammates, Bucciarati keeps a stern facade of determination, ordering his team to carry on despite the recent loss of Abbacchio even though he too was internally distressed by Abbacchio's sudden death.[14]

Bruno keeps a strong relationship with his team, being severe but fair and giving them praise whenever he think it is earned. His habit of looking for misfits and treat them humanly has indeed secured their loyalty, allowing the majority of the group to stay united under him even when they rebel against the Boss of Passione. Furthermore, each member of Bruno's team look up to his ability and believe that under his leadership that they can achieve greatness. For instance, Guido Mista was freed out of prison thanks to Bruno, and Narancia was struck by Bruno's stern but humane behaviour toward him, both ultimately trusting him to win against Passione. Bucciarati is shown to have a paternal side with Narancia, whom he sheltered and counseled to stay away from the life of a gangster,[10] as well as with Trish whose worries about being the daughter of a mob boss he tries to comfort the best he can.[13] In the brutal world of gangsters, Bruno nonetheless holds no illusion that they are also constantly risking their lives.