Abstract: Breast Self-examination (BSE) appears to be an effective method for earlier detection of breast cancer. Because health behaviors usually result from healthy beliefs, so the cognition of these beliefs related to breast self examinations is essential to design program for promoting this activity. The present study evaluates the healthy beliefs of 420 nurses about BSE in 21 therapeutic centers of Tabriz. Most (90%) of nurses received information about breast cancer and BSE and most (70.2%) nurses had practiced it and frequency of BSE in majority (39%) of nurses was every 2 months and more. Level of perceived susceptibility in most nurses (58.1%) was moderate, level of perceived seriousness in most nurses (56.6%) was good, level of perceived benefits in most nurses (81%) was good, level of perceived barriers in most nurses (52.9%) was poor and level of perceived confidence in most nurses (57.4%) was moderate. Also, there was significant relations between some nurses characteristic and variables of Health Belief Model (p<0.05). Because level of perceived susceptibility and confidence in most nurses was moderate, the provision of specialized training programs in BSE may reinforce positive health beliefs, modify poor health beliefs, increase the awareness of breast cancer and improve the practice of BSE among nurses.