Information related to contraception discontinuation, especially in the context of Nepal is very limited. A nested case-control study was carried out to determine the factors affecting discontinuation of intrauterine contraceptive devices (IUCDs). A total of 115 cases (IUCD discontinuers) and 115 controls (IUCD continuers) were randomly selected based on the data obtained from the user’s record of a family planning center in Kathmandu. Matching criteria were age during insertion and date of insertion of IUCD. Logistic regression was used to analyze the data. When cases were compared with controls, the results showed that place of residence, sex of last child, reproductive intention, experience of side effects, and follow-up practice were associated with discontinuation of the IUCD. Experience of side effects has been seen as the major reason for discontinuation. The results suggest that side effects after IUCD insertion should be properly discussed and promptly treated to reduce the discontinuation rate.