Patients with attention-deficit/hyperactivity disorder (ADHD) suffer from inattention, hyperactivity, and impulsivity. Clinicians often assume that the specific difficulties associated with ADHD are bound to affect sexual behaviors, and favor risky sexual behaviors, thereby increasing the frequency of sexually transmitted diseases (STDs). This review provides an up-to-date synthesis of the literature concerning STDs in patients with ADHD. A systematic review of the literature was performed using the PubMed, PsychInfo, and Embase databases, with STDs as the main outcome measure. Patients with ADHD report more STDs than the general population. Results are limited by the small number of existing studies, as well as the heterogeneity of the outcome measures. Findings from this first systematic review of data on STDs in individuals with ADHD suggest that ADHD affects sexual health and sexual behaviors. Clinicians treating patients with ADHD should explore risky sexual behaviors in their patients and raise awareness about the risk of contracting STDs. Further studies are warranted to better evaluate the risk of contracting an STD in patients with ADHD.