Services of Family planning have an essential role for improving the quality of family's lives and also their economic welfare. Family planning methods may lead to menstrual changes such as menorrhagia, oligomenorrhea or inter-menstrual spotting. Aim of the study: to assess the effect of contraceptive use on menstrual cycle patterns among clients attending family planning clinics in Assiut City and to assess the effect of menstrual cycle side effects on contraceptive discontinuation among these clients. Subject and Methods: This prospective study was conducted on1570 clients in F.P. clinics serve the west sector of Assiut city by using a structured interviewing and follow up questionnaires. Results: There are statistical significant differences between case &control group as regards Monthly Injectable, the combined pills and Progestin-Only Injectable used and menstrual disorders respectively. There is statistical significant difference between different method of family planning methods and discontinuation rate (P.V=0.008) and between contraceptive methods and its side effects at the first and second follow up (P.V= <0.001 and 0.001) respectively. Conclusions: Contraceptive use significantly affects the menstrual cycle and discontinuation rate of its users. Recommendations: Contraceptive counseling must be included knowledge about menstrual pattern changes. More researches should be done to assess the impact of family planning counseling on reducing the rate of unwanted pregnancy.