Background: Breast cancer is the most common form of malignancy among females. Family history is a key risk factor for breast cancer. Breast cancer screening practices are vital in patients with family history of breast cancer. Telephone counseling and education may be appropriate for improved breast cancer screening. This study was done to determine family caregiver patients’ knowledge of risk factors for breast cancer and practice of breast cancer screening and also to assess the effect of telephone counseling and education on mammography screening.Methods: This study was a community-based trial. The participants of the study were 90 caregivers who were randomly divided into an experimental group, telephone counseling and education, and a control group. The intervention group received counseling and education phone calls. A three-section questionnaire was responded and filled out through telephone interviews with the participants. The collected data were analyzed with SPSS18, using descriptive and inferential statistics.Results: The results showed that 88.9% of the participants did not know when to do breast self-exam (BSE). Mammography was performed by the participants before and after the telephone counseling in intervention group (P<0.00), which were 13.3% and 77.8% respectively). Moreover, the major cause of failure to participate in mammography was lack of enough knowledge in 73.3% of the participants.Conclusion: This study concluded that knowledge and practice on breast cancer screening in family caregiver of breast cancer patients was low. Telephone counseling and educating may provide a suitable technique for earlier detection of breast cancer in family caregivers of breast cancer patients and it can influence the decision making regarding mammography screening among 40-year-old or older women. Trial Registration Number: 2017052316870N3