Summary It is paramount to assess the psychometric properties of self-assessment tools in order to check the tests' reliability and validity, also to enable proper outcome interpretation. Aim to check the psychometric properties of the IOI-HA (International Outcome Inventory for Hearing Aids) in its Portuguese version, called QI-AASI (International Questionnaire - Individual Sound Amplification Device), in terms of internal uniformity, correlation between the items and reproducibility. Study design: descriptive, observational and cross-sectional. Materials and Methods the questionnaire was deployed to 53 hearing aid users, 34 females and 19 males, with ages between 19 and 92 years - from incomplete basic education to complete higher education, encompassing subjects with monoaural and binaural sound amplification. Results the QI-AASI had a Cronbach Alpha of 0.69. In the correlation among the items, there were numerous significant correlations. The instrument was properly reproducible, except for item # 6, which presented a significant difference in comparing test and the retest. Conclusions the QI-AASI is suggested in the rehabilitation process of users of hearing aides; nonetheless, the questionnaire can be difficult for subjects with low social and economic status when self-employed.