Introduction: Regret after sterilization, not only requires an expensive surgical procedure for recanalization, but also can affect the couples’ inter and intra-relationships. Whence, undergoing sterilization in Sistan and Baluchestan has the lowest rate compared to other provinces, the habitants’ regret after sterilization may further discourage other volunteers of the procedures. Therefore, this study was launched to determine the regret rate among sterilized people and to explore the underlying causes to help policy-makers improve the way people approach contra-ception and increase their participation. Materials & Methods: this cross-sectional study was done on 100 men and 144 sterilized women selected based on random sampling from 12 rural health and vasectomy counseling centers in Zahedan and Zabol during 2006. A questionnaire was developed and completed by the researchers through interviews. The questionnaire included questions on demographic characteristics, reason (s) for sterilization, reason (s) for regret and kind of complications upon sterilization, and their sources of information on the issue. The data were analyzed by using frequency tables, chi-squared, t-test, and logistic regressions. A p-value <0.05 was considered as the level of signifi-cance. Results: The mean age of sterilized men and women was 41.8±7.6 and 40.6±5.5 years and mean age at the time of sterilization was 38.2±6.7 and 36.3±4.3, respectively. Completion of family size was reported to be the main reason for sterilization by 44% percent of men and 58% of women. In the two groups, 17% of men and 12.5% of women expressed regret after sterilization and believed complications were the most important factor; mostly due to physical complications, and partly because of psychological factors and mood disorders ─ although, it seems that some of these complications have no direct relationship to sterilization. The chi-square test showed signi-ficant differences between the rate of complications and regret rates after sterilization in both men and women (p<0.001). Conclusion: The results showed that complications due to sterilization are the main causes of regret. Therefore, it is necessary to pay more attention to mentioning the probable complications of the procedures such as low back pain, weight gain and mood disorders in women and pain, swelling and decreased libido in men during pre-sterilization counseling; post-sterilization coun-seling is also encouraged for increasing satisfaction rate in these volunteers.