OBJECTIVES: To assess the patients´ and their accompanying family members or carers´ value attributes and perceptions about GD when compared to the corresponding brand name drugs (BD). METHODS: 25 patients and 25 accompanying persons were consecutively selected and interviewed while visiting 6 commercial pharmacies located in different regions of São Paulo city. Also 25 patients and 25 accompanying persons were consecutively selected and interviewed while waiting for their regular outpatient visits at the university outpatient clinic. The questionnaire consisted of questions regarding socio-economic, demographic and educational items, quality of life (QoL), and the interviewee perception regarding the value attributes of GD when compared to BD. The study was approved by the local ethic committee. RESULTS: Respondents were predominantly women (57%) and the mean age was 54 years. Additionally, 55% relied exclusively in public healthcare system and 55% were regularly employed. Mean QoL as assessed by SF-6D was 0,74. Respondents overwhelmingly (99%) believed GD to be cheaper than BD. Some 36% and 63% also reported GD to be less and equally effective, respectively, as compared to BD. GD were perceived as either safe or less safe than BD in 46% and 46%, respectively. Some 74% of the sample agreed with the statement that they would prefer to take a BD if there was no price difference to the GD, and 85% admitted they regularly compare the prices of BD and GD before deciding which drug to buy. CONCLUSIONS: Multiple factors may contribute to the decision to buy a GD. Among these perceived effectiveness, safety and price appear to be the most important factors. Further studies are needed to better understand the decision-making process regarding GD use and its consequences for the healthcare system and families.