Background: Attention-deficit hyperactivity disorder (ADHD) and entrepreneurship are two concepts that have recently received attention from researchers. Objectives: This study aimed to find the relationship between ADHD symptoms and entrepreneurial behavior with the mediating role of entrepreneurial self-efficacy and attitude, as well as to assess the relationship between entrepreneurial self-efficacy and entrepreneurial behavior with the mediating role of entrepreneurial attitude. Methods: This study was conducted on 388 Iranian entrepreneurs in 2021. The Entrepreneurial Behavior Scale, the Entrepreneurial Attitude Questionnaire, the Entrepreneurial Self-efficacy Scale, and the Adult ADHD Self-report Scale were used to collect the data. Data were analyzed using Mplus software (version 8). Results: The results revealed that hyperactivity/impulsivity symptoms were positively and significantly related to entrepreneurial behavior (P < 0.001), and attention-deficit symptoms were negatively and significantly related to entrepreneurial behavior and entrepreneurial attitude, mediated through entrepreneurial self-efficacy (P < 0.01). Conclusions: Our findings suggest that the entrepreneurial behaviors and entrepreneurial attitudes of individuals with ADHD symptoms depend on their entrepreneurial self-efficacy. Our findings hold important implications for empowering individuals with ADHD symptoms in the entrepreneurial path.