Abstract Introduction : Formative assessment (FA) is an assessment concept that is of interest in education. The Doctor of Pharmacy program is one of the programs in which FA is usually implemented. This study aimed to describe the correlation between FA scores and summative assessment (SA) scores and to suggest possible key success factors that affect the effectiveness of FA. Methods This study employed a retrospective design using mixed methods for data collection. Data in the semesters 1/2020 and 2/2020 of the Doctor of Pharmacy curriculum in a Thailand pharmacy school were used. Three sets of data were gathered, including the course information (e.g. FA methods, FA scores, and SA scores) from 38 records, self-reports from 326 students and 27 teachers, and 5 focus group discussions. The quantitative data were statistically analyzed using descriptive statistics and Pearson correlation, while the qualitative data were analyzed using a content analysis framework. Results The analysis revealed five main methods that were used for FA, including individual quizzes, individual reports, individual skill assessments, group presentations, and group reports. Of all 38 courses, 29 (76.32%) had significant correlations between FA and SA scores at p-values