Background: Implanon has been described as a safe and highly effective, long-acting, reversible progesterone-only implant. Like other reversible contraceptives, it has side effects which could lead to its discontinuation. Objectives: To determine the prevalence rate, side effects, discontinuation rate, and reasons for discontinuation of Implanon at Rivers State University Teaching Hospital (RSUTH), Port Harcourt. Methods: A retrospective study of 874 clients, who attended the clinic at the RSUTH from 1stJanuary 2015 to 31st December 2019 was carried out. Records were retrieved and reviewed. Data was extracted, coded, and analysed using the Statistical Package for Social Sciences (SPSS) IBM version 25.0 (Armonk, NY). Results: Of 874 contraceptive acceptors, 283 (32.4%) accepted Implanon. Most of the clients, 136 (48.1%) were between the age range of 30-34 years, 277 (97.9%) were married and 224 (79.1%) multiparous. Two hundred and eighty (98.9%) were Christians and only 1(0.4%) client had no formal education. Majority of the clients -153 (54%) had tertiary level of education. One hundred and seventeen (41.3%) of the acceptors did not use any method of contraception prior to the first visit. The discontinuation rate was 25.8% and the most common reason for discontinuation was the desire for pregnancy. Most of the clients, 62 (62.6%), reported side effects of irregular vaginal bleeding and menorrhagia. The Pearl index was 0.14/100 woman-years. Conclusion: The prevalence and discontinuation rates of Implanon were low. Irregular vaginal bleeding and menorrhagia were the most common side effects while desire for pregnancy was the most common reason for discontinuation.