Objectives The aim of this study is to determine the 12 months’ discontinuation rate and associated factors among family planning clients using pills and injection. Methods A follow-up study was initiated to collect data from 845 family planning users between November 2017 and December 2018. An interviewer administered questionnaire was used to collect data from participants. Data were entered into EpiData version 3.1 and analyzed using SPSS version 20, where both are open-source systems. A Cox proportional-hazards model was used to estimate the hazard ratios (HR) for the rate of discontinuation among participants. Result At 12 months, 63.5% of women discontinued the use of their baseline method. For the individual methods, 84% of women that chose the pill discontinued its use and for those using the injectable, 60.7% of women discontinued its use. Using the adjusted Cox proportional-hazards model, pills users (HR = 1.77; 95%CI = [1.4–2.3]), users receiving family planning services in the same room as other maternal health clinic services (HR 1.58; 95%CI = [1.16–2.2]), users served by health officers (HR = 3.7; 95%CI = [1.66–8.2]), and users not intending to use the baseline method continuously (HR = 1.6; 95%CI = [1.16–2.24]) were significantly more likely to discontinue using the baseline method. The main reason cited for discontinuation was side effects of contraception. Conclusions The discontinuation rate of the baseline contraceptive method after 12 months was very high. To increase the continuity of contraceptive use, family planning services should be given in a separate room with effective counseling on potential side effects, provided by midwives or nurses who have good counseling skills.