While student-run clinics are often important healthcare safety nets for underserved populations, their efficacy for improving patient health knowledge has not been thoroughly explored. From September 2011 to April 2012, we assessed patients' retention of hepatitis B virus (HBV) knowledge after receiving student-led education at two student-run HBV screening and vaccination clinics. Patient education was provided by trained first and second-year medical, nursing, and pharmacy students, aided by a script and interpreters. Patient knowledge of HBV was evaluated at three points: before education, after the initial visit, and at one-month follow-up. Student-led education produced improved knowledge of HBV transmission, prevention, and management, which was retained 1 month after education for 52 patients tracked through time. Mean scores on an HBV knowledge survey improved from 56.4 % (SD = 15.2 %) at baseline to 66.6 % (SD = 15.1 %) after education, and 68.3 % (SD = 15.2 %) after one month. There was a statistically significant difference between the first and second (paired T test, p < 0.001) and the first and third tests (paired T test, p < 0.001), but no difference between the second and third tests (paired T test, p = 0.45). Multivariate analysis demonstrated that retention was correlated with patient educational background but independent of patient age, gender, income, primary language and number of years lived in the United States. Our study suggests that trained health professional students can effectively impart health knowledge that is retained by patients for at least 1 month. These results warrant consideration of student-led educational sessions at SRCs as a promising community health education model.