In this study, we aimed to prepare and validate an Indonesian version for the Screening Tool of Older People's Prescriptions (STOPP), which is an instrument to identify inappropriate medications for elderly patients. Methods: The Indonesian version of STOPP (STOPP_INA) was developed using modified transcultural adaptation guidelines from the American Academy of Orthopedic Surgeons. Our method consisted of translating original STOPP into Indonesian (forwardly translation), synthesis of forward translation, translation into English and synthesis of back translation, a review by the copyright holder of STOPP, a review by the expert team, pretest, revision of STOPP_INA, field test, and psychometric analysis of the final version of the questionnaire. The study design for this part was quasi-experimental with purposive sampling for members of the translator's team, expert's team, and respondents in the pretest, but they were different from field testing that used purposive and postsurvey sampling for respondents. Content validity and face validity were used to construct the validity of STOPP_INA by assessing item-level content validity and correlation between items and total values. Internal consistency was measured with Cronbach's alpha coefficient. Findings: The expert panel agreed on a list of 81 criteria. Five (62.50%) of expert team members agreed and could be continued to the field test without revision of STOPP_INA and 3 (37.50%) agreed with a revision. The research subjects in the psychometric test had 230 respondents, 5 (2.17%) resigned, with an average of item-level content validity index of 0.99. The construct validity analysis showed that 5-item criteria are “not valid,” namely in A1, A3, B7, B10, and C3. Reliability analysis showed the Cronbach's Alpha and Cronbach's Alpha Based on Standardized Items were 0.978 and 0.979. Conclusion: The expert team was be agreed on 81 criteria (100%) of adaptation of STOPP version 2 criteria. There were 5 criteria that not valid statistically, they could not be removed from the instrument because they can influence content and construct of the instrument. The STOPP_INA has been developed for the Indonesian population, currently being tested in clinical practice against elderly patients undergoing hospitalization.