Background: The potential benefits of ayahuasca on mental health conditions are well documented. This pilot study is the first to explore whether there is an association with ayahuasca use and reductions in inattention, hyperactivity and impulsivity, the core features of attention-deficit/hyperactivity disorder. Methods: In this exploratory, observational pilot study, the Adult Attention-Deficit/Hyperactivity Disorder Self-Report Scale was administered to 49 adults (23 males, 24 females, two participants did not report their sex) prior to and following the completion of ayahuasca retreats facilitated by the Ayahuasca Foundation in Iquitos, Peru. Only four participants self-reported having a diagnosis of attention-deficit/hyperactivity disorder. Participants attended either an 8-day (four to five ceremonies), 2-week (six ceremonies), 3-week (eight ceremonies) or 4-week (three to 11 ceremonies) retreat. Results: Inattention, hyperactivity/impulsivity and total scores significantly reduced following an ayahuasca retreat, irrespective of the length of that retreat and the number of ceremonies participants attended. Conclusions: This pilot study is the first to find reductions in self-reported inattention, hyperactivity and impulsivity in a sample of mostly non-attention-deficit/hyperactivity disorder adults following the use of ayahuasca. However controlled trials are required to determine causality. Research and clinical implications are considered.