Background: Breast cancer is one of the most common health problems and the most important cause to threaten women's lives; however, its complications can be prevented by a timely diagnosis and effective therapeutic measures. Objectives: The aim of the present study was to determine the effect of motivational interviewing (MI)-based training, as compared with conventional training, on the frequency of breast cancer screening tests in female teachers in Zahedan during the year 2017. Methods: This is a quasi-experimental study with a pretest-posttest design, which was carried out on 140 female teachers teaching in different levels of study in Zahedan, Iran, during the year 2017. Schools were selected randomly from two education districts using a multistage sampling method. The participants were divided into an intervention group receiving MI-based training (N = 70) and a conventional training group (N = 70). Training was provided to the MI-based training and conventional training groups based on the specified content during three sessions. Data collection was carried out using a demographic questionnaire and a screening test record form 20 weeks after the training. The frequency of breast self-examination, breast clinical examination, and mammography was evaluated. Data analysis was then conducted using the chi-square test, independent t-test, and paired t-test in SPSS version 21. Results: After 20 weeks of training, breast self-examination was regularly practiced by 58.2% and 40.3% of women in the MI-based and conventional training groups, respectively (P = 0.02). The clinical breast exam (CBE) was carried out by 25.4% and 14.9% of women in the MI-based and conventional training groups, respectively (P = 0.09). Mammography was also done only by 10.4% and 4.5% of women in the MI-based and conventional training groups (P = 0.16). Conclusions: MI-based training increased women's adherence to breast self-examination. Considering the positive effect of this approach on increasing the adherence to some breast cancer-screening behaviors, it is recommended to determine the effectiveness of this training method in other groups of women to increase the generalizability of the results.