A whimsical, dishonest, and elusive personality. Possessing perverted sexual preferences, his targets of interest do not distinguish between age or gender. He feels joy and excitement in hunting prey he likes, and his motto is to keep promising people alive without killing them, even if it means stalking or temporarily guarding them while they are still growing. Toward his big favorites, Gon and Killua, he is a hardcore, crazed psychopath whose lower abdomen reacts just by imagining hunting them once they have grown. He looks forward to one-on-one matches with strong opponents, enjoying the reading of the battle, saying "Battle is a dance." On the other hand, he is thoroughly cruel and indifferent to people he judges as "worthless/no potential" (Hunter Exam candidates, failing Pro Hunters, Association-exclusive Hunters, etc.). He feels no emotion even if he kills them to kill time or out of frustration, or uses them as disposable tools. Due to these kinds of human relationships, he has no "eccentric friends" who would actively provide him with information, and as a result, as a Hunter, he is remarkably indifferent to world news and surrounding information. Regarding the Chimera Ants, which might have been a force powerful enough to clearly entertain Hisoka, he didn't even know they existed, so he lost a potential opportunity to fight. Also, due to his combat preferences described later, the Ants are "outside the scope" of his desires.

Despite being a so-called battle maniac, his mind works very fast and he is quick-witted, whether in combat or normal times. When Chrollo used "Lovely Ghostwriter" to tell the fortunes of the members, Hisoka's prophecy would have immediately revealed him as a traitor to other members, but using the aforementioned "Texture Surprise," he altered the prophecy into content that could be interpreted in a way convenient for him in the short time it took for Pakunoda to ask to see it. He also possesses mental strength, not changing his expression no matter how much damage his body takes or even if he loses limbs; he even tries to use that to shake the opponent's mind. Perhaps because he is aware of having killed many people, he has a philosophical side, thinking that his time to die will come someday. When he was actually pushed to the brink of death, he only showed a reaction like "Am I... going to die?" and instead, as if enjoying even that situation, he unhesitatingly used a gambling-like method where he couldn't predict at all whether he would win or lose the bet. (As a result, it can be said that he "won" the bet.)