Breast and cervical cancers impose large costs on society. Performing breast and cervical cancer screening tests (BCCST), considered as a health promotion behavior, is therefore important. This qualitative study based on the “integrated model of planned behavior and self-efficacy (PBSEIM)” was conducted to assess influencing factors. A total of seventy female workers aged between 20-45 years from Tehran suburban factories were recruited by purposeful sampling to participate in ten focus group discussions. Data were analyzed using the conventional content analysis method. The majority had an appropriate attitude toward BCCST, stressing the importance of family’s especially husband’s encouragement as the subjective norm. Low knowledge, depression, fatigue, shyness and fear of examination and diagnosis of cancer, poor quality of services and financial barriers were mentioned as effective negative factors. The majority reported low self efficacy for planning to perform the behavior and had no intention toundergo screening in the next three months. So interventions are necessary to overcome effective barriers and improve women’s health.