AIMS: Adults with attention-deficit/hyperactivity disorder (ADHD) often exhibit heightened risk-taking behavior due to disadvantageous decision-making. This study investigates the influence of preceding unconscious and affectively driven processes on this behavior, with a focus on sex-specific effects. METHODS: Functional magnetic resonance imaging was used to examine neural activity during the anticipation phase of decision-making in 18 individuals with ADHD (10 females and 8 males) and 20 healthy controls (10 females and 10 males) using a modified version of the Balloon Analogue Risk Task. RESULTS: During the anticipation of decision-making, individuals with ADHD exhibited reduced activation in the right precuneus and the right superior frontal gyrus compared to healthy controls. Sex-specific effects were exclusively observed within the ADHD group, showing increased neural activity in females compared to males in areas including the dorsolateral prefrontal cortex, left insula, right caudate, right cuneus, and precuneus. CONCLUSION: These findings indicate altered neural activity in adult patients with ADHD with sex-specific differences during the anticipation of a risky decision. The study underscores the importance of the right precuneus and superior frontal gyrus in relation to metacognitive functioning and interoceptive awareness. However, further research is needed to explore the interplay of unconscious processes during decision-making in ADHD.