Flipped classroom pedagogy has been shown to improve nursing students' academic performance. The study aimed to determine the effect of a flipped classroom approach on students' pharmacology assessment scores in a school of nursing in Karachi, Pakistan. A retrospective chart review was performed. The pharmacology test scores of the BSc nursing cohort of 2020, when flipped classroom pedagogy was used, was compared with those of the BSc nursing cohort of 2019, where traditional pedagogy was employed. Students' summative evaluation for the course and their verbal feedback were analysed. The median continuous assessment test score of the 2019 cohort was 35 (interquartile range (IQR) 32-38), while that of the 2020 cohort was 38 (IQR 35-41). The difference in the score was statistically significant (P<0.001). The study gives an insight into a relatively novel pedagogy that was found to improve pharmacology knowledge test scores among nursing students.