This study measured the impact of a purposeful aerobic laughter intervention on employees' sense of self-efficacy in the workplace. Participants were 33 employees of a behavioral health center. They met for 15-minute sessions on 15 consecutive workdays and engaged in a guided program of non-humor dependent laughter. The primary outcome measure was the Capabilities Awareness Profile, a self-report self-efficacy questionnaire. Employees demonstrated a significant increase in several different aspects of self-efficacy, including self-regulation, optimism, positive emotions, and social identification, and they maintained these gains at follow-up. Purposeful laughter is a realistic, sustainable, and generalizable intervention that enhances employees' morale, resilience, and personal efficacy beliefs.