Purpose: This preliminary pilot effort assessed the effect of group counseling using A-B-C technique on irrational beliefs and self-efficacy for women health volunteers (WHVs) in breast self-awareness. Design: In this randomized controlled trial, 40 WHVs from three health centers (Abhar, Iran) were randomly allocated into two groups. Method: Seven weekly group counseling sessions were held for the intervention group. Data about cancer fatalism belief, dissatisfaction of body, anxiety, and self-efficacy were collected through validated questionnaires 1 month before and 2 weeks after the intervention. Results: Mean scores of anxiety (p = .036), body dissatisfaction (p = .002), cancer fatalism belief (p ≤ .0001), and self-efficacy (p ≤ .0001) were improved in the intervention group compared with control group. Discussion/Conclusion: Group counseling using A-B-C technique was effective in improving irrational beliefs and self-efficacy of the WHVs about breast self-awareness. Implications for Practice: The findings may help in further development of strategies and cultural programs to improve health-related irrational beliefs.