Objective.To analyse the medicines prescription, prescription filling, payment expenditure for medicines by ambulatory health service users (HSU) in 2006, and to evaluate its evolution in the last 12 years. Material and Methods. Using data from the National Health Surveys in 2006 three binary logistic regression models were constructed to identify the variables associated with the prescription rate, prescription filling and payment for medicines in 2006.The results of access to medicines were compared to the ones from previous National Health Services from 1994 and 2000. Results.The type of health service provider was found to be the most important predictors of access to medicines. Although the proportion of HSU obtaining a prescription and paying for drugs has broadly stayed the same as in 1994, the percentage of HSU paying for their prescribed medicines decreased from 70% in 1994 to 42% at Ministry of Health institutions in 2006. Conclusion.The progress in prescription and population access to medicines has been uneven across health service providers.