Evidence suggests that slow paced diaphragmatic breathing (DB) can significantly affect prefrontal cortex functions through increasing an individual’s physiological self-regulatory capacity. The current research demonstrates the effects of paced DB on inhibitory control, which is considered to be a reliable measure of behavioral self-regulation. Eighty healthy participants were randomly assigned to one of two conditions (20 males and females each). Participants were instructed on either DB at a pace of six-breaths per minute (BPM) or instructions on environmental awareness and asked to breathe at 12 BPM. Following training, all participants completed a computer-based task designed to examine inhibitory processes. Physiological recordings of heart rate (HR), BPM, and HRV were collected at baseline, during the breathing training, during the cued go/no-go task, and after the cued go/no-go task. The findings demonstrated that the DB condition had significantly lower BPM, HR, and higher HRV (p’s<0.05) during active training than the environmental awareness condition. Furthermore, the DB condition performed significantly better on the measure of inhibition than the environmental awareness condition (p<0.05). The use of DB as a reliable method to increase physiological self-regulatory capacity and improve behavioral self-regulation, measured as inhibitory control, should continue to be explored.