The objective of this study is to evaluate the psychometric properties of a user satisfaction scale regarding the Brazilian National STD/AIDS Program, specifically related to dispensing AIDS medicines. The scale was developed and applied in a study covering 10 Brazilian States that evaluated the quality of medicine dispensing. The questionnaire was answered by 1,412 people living with HIV and undergoing antiretroviral therapy. Construct validation involved two stages of factor analysis. The item-total correlation matrix was analyzed, and tests for associations between the target variable, socio-demographic variables, and related constructs were performed. Reliability was studied by means of the sub-scales' internal consistency, estimated by Cronbach's alpha. Five relevant satisfaction dimensions were identified. A moderate level of internal consistency was found for these dimensions, suggesting they were adequate. The results of the association tests agreed with other studies reported in the literature. We conclude that the instrument is appropriate for application in similar populations with adequate psychometric characteristics and serves to measure users' assessments of the pharmaceutical services received and helps to orient improvements in such services.