OBJECTIVES: To estimate the relative cost effectiveness of available contraceptives in a pacific region country (Colombia) from a social perspective. METHODS: A Markov model was constructed to simulate costs for 13 contraceptive methods and for no contraceptive method over a 10-year period, with a 5% discount rate. Failure rates, adverse event rates and resource utilization were derived from literature. Sensitivity analyses were performed on costs and effectiveness rates. RESULTS: The 4 least expensive methods per person month were: copper-T IUD (USD $0.34), vasectomy (USD $1.28), tubal ligation (USD $1.44) and implant (USD $2.19).  The cost-effectiveness analysis of methods to prevent pregnancy showed: the Copper T IUD has a ratio of incremental cost-effectiveness (ICER) of USD $ 5,540 (per month, per pregnancy avoided) when it is contrasted with the vasectomy. The Vasectomy is dominant compared to tubal ligation, and it presents an ICER of USD $ 7.371 in relation to implant methods. Comparing Copper T with the second most affordable reversible method, an ICER of USD $ 12,033 was obtained. The order of results did not change with a discount rate of 0% but were sensitive to the time horizon. CONCLUSIONS: Differences in time horizon are influential factors that determine the dominance of contraceptive methods. It is noteworthy that although the cost of a tubal ligation and a vasectomy is the same, the total costs for a vasectomy are lower due to reduced complication-related costs. Given that the monthly premium of the compulsory health insurance in Colombia for a woman of childbearing age (19-44 years) is USD $ 22, the value of USD $ $12,033 or $5,540 per month to prevent pregnancy through implant or vasectomy is excessive. Therefore, according to the case analysis, the Copper T is a cost effective option for Colombia, including reversible and non- reversible methods.