Objective: The present study was conducted to evaluate and compare the retention of clinical pharmacology knowledge among the students who had completed the Integrated Basic Medical Sciences program. Methods: This was a crosssectional study carried out among the 2 nd year exit students of National Medical College, Birgunj, Nepal during the month of September 2013. Students' responses were collected through a survey questionnaire prepared on the basis of renowned pharmacology text books including Katzung's Basic and Clinical Pharmacology, Bennett and Brown's Clinical Pharmacology, Goodman and Gilman's the Pharmacological Basis of Therapeutics and Rang and Dale's Pharmacology. The questionnaire was distributed among the participants and they were requested to tick the correct response independently. Data were entered in SPSS version 11.5 and evaluated for descriptive and inferential analyses using the Chi square test and Paired samples t test. Results: About 58% of the students were males and more than 66% of the total students were from different parts of India. The mean scores ± standard deviations from the syllabus of first and second years were 9.08 ±3.34 and 11.67 ±3.54 respectively; and the scores were positively and significantly correlated (r=0.542, p<0.001). The difference in means of scores was 2.59 (95% CI: 2.02 to 3.15). Conclusions: The retention of clinical pharmacology knowledge is significantly lower from the first year syllabus than that from the second year which clearly indicates a decline in clinical pharmacology knowledge with passage of time.