Background: Depot Medroxyprogesterone acetate (DMPA) and Norethisterone Enanthate (Net-En) are frequently used progestogen-only injectable contraceptives in many developing countries including Nigeria. Their use is often complicated by abnormal and unpredictable menstrual bleeding patterns. This has often been a source of worry to clients and their spouses leading to method switch or discontinuation. Method: A structured questionnaire was administered on 354 clients who were on intramuscular DMPA 150mg 3-monthly or intramuscular norethisterone enanthate 200mg 2-monthly and a matched control group of 323 clients at the Reproductive Health Center of the Ahmadu Bello University Teaching Hospital Zaria, Nigeria. Data was analyzed using Minitab statistical software. Results: Abnormal menstrual bleeding, commonly amenorrhea and irregular bleeding, were significantly associated with use of either DMPA or Net-En. Clients tolerated amenorrhea better than irregular bleeding and their preference for either DMPA or Net-En was not altered by amenorrhea. Irregular bleeding was a significant reason for method switch or discontinuation. Conclusion: Treatments that can inflict amenorrhea could be acceptable options in the management of abnormal bleeding patterns induced by progestogen-only injectable contraceptive which are in present use. Keywords: depot-medroxy progesterone acetate, norethisterone enanthate, menstrual abnormalities Annals of African Medicine Vol. 4(4) 2005: 144β14