background and aim: within the population attended by the costarican social security system (ccss), there exists a minority group with unique needs of certain drugs due to their differential clinical condition. in this situation of importance, although only constituted by a minority of cases, the ccss provides a system for acquiring “transit drugs” and those which are outside of the official list of medicines. the acquisition process involves a variety of public administrative procurement procedures established by law, which affect the prescription of medication to the patient. this study aims to analyze the duration of the process of public procurement and bidding involved in the direct purchases of drugs not in the official list of medicines by the hospital mexico in 2009. methods: in this research we reviewed a 47.26% of the total population of public procurement records, corresponding to 112 of the 237 direct procurement and tendering records which are listed in 2009, according to the historical procurement of 2009. results and conclusion: it was determined that there is a high variability between different public procurement processes, and between different processes carried out in each of these posters. there is no uniformity in regard to the procurement processes, making it difficult to determine the factors that hinder them.