Black youth account for the largest number of new HIV infections among heterosexual youth. Mental illness and difficulties in emotion regulation contribute to increased reports of HIV/sexually transmitted infection (STI) risk‐related sexual behaviors in this group. Yet limited interventions exist to address this affective component of the sexual decision‐making process. The purpose of this paper was to describe the trial design, research challenges, and baseline characteristics from a study designed to fill this gap. Project GOLD was a pilot randomized controlled trial of a psychoeducational HIV/STI prevention intervention designed to address the role of mental illness and emotion regulation in HIV/STI risk among heterosexually‐active Black youth aged 14 to 17 (N = 108). Challenges encountered in the research process warrant further attention in future research (e.g., disagreement among the regulatory bodies on parental permission requirements). The most common mental health diagnoses were Recurrent Major Depressive Disorder (15.7%) and current substance abuse (7.4%). Participants reported higher levels of emotional suppression, and adaptive methods of emotion management, than culturally inappropriate expressions of anger or sadness. They also reported a mean age of 13.6 at first vaginal sex, used condoms 66% of the time for vaginal sex, and had an average of three sexual partners in the past 6 months. More than one‐quarter (26.9%) had sex with more than one person in the same day. These findings indicate intervention is crucial for this population. The forthcoming trial evaluation will indicate the promise of such interventions in reducing HIV/STI infections in this key population.