RATIONALE, AIMS, AND OBJECTIVES: Counselling is essential in drug dispensing, since it enables patients to receive and understand the information to correctly use their medicines. Although counselling is a quality indicator on drug dispensing, models that guide pharmacists in this practice are scarce. Thus, this study aimed to develop and validate the content of an instrument to support pharmaceutical counselling for dispensing of prescribed medicines. METHOD: A two-stage validation study was conducted out from February to October 2017. The first stage involved the development of the instrument, and the second involved content validation. Instrument development included the following three steps: (1) drafting of the prototype; (2) an academic brainstorming meeting, and (3) a pre-Delphi process. Content validation was then conducted using the Delphi technique. At this stage, 40 pharmacists who were experts in drug dispensing, were invited to assess the instrument. Consensus among experts was calculated according to the content validity index (CVI). RESULTS: The development stage generated three versions of the instrument: the prototype, Version 1 (modified after brainstorming meeting), and Version 2 (modified after the pre-Delphi process). Version 2 underwent the content validation process, in which 29 pharmacists participated during the first round (rate of return: 72.5%) and 23 of these during the second round (rate of return: 79.31%). All items obtained CVI > 0.82 and were thus considered to be validated. The final instrument comprised three components: suggestions for questions, dispensing process reasoning, and suggestions for counselling, and other conduct in 11 stages, each representing a step in the clinical reasoning process. CONCLUSIONS: An instrument was developed to support pharmaceutical counselling for dispensing of prescribed medicines, suggesting main questions, counselling, and conduct to be taken by pharmacists, and its content validity was verified.