BACKGROUND Unprotected sun exposure could cause tanning, burning, hyperpigmentation, skin aging, and even skin cancer. Regular sunscreen use is a safeguard and a primary preventive strategy against sunlight-related damages. This study aims to find out the prevalence of sunscreen use among medical undergraduate students of a medical college of Eastern Nepal. METHODS A descriptive cross-sectional study was conducted among the current medical undergraduate students of 2 medical colleges in Nepal on sunscreen use from September 2020 to October 2020. Convenience sampling was done to reach the sample size of 300. Data collection was done after taking ethical approval from the Institutional Review Committee (IRC/1778/020). Data analysis was done by using Statistical Package for the Social Sciences version 11.5 software. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. RESULTS The prevalence of sunscreen users was found to be 227 (75.67%) (70.81-80.52 at 95% Confidence Interval) among whom only 35 (15.41%) were regular users. Majority 144 (63.43%) applied sunscreen only on the face, 72 (31.71%) considered reapplication, and 155 (68.2%) knew the Sun Protection Factor value of their sunscreen. Cosmetic sunscreen was considered by the majority of the users 151 (66.51%). Greasy feeling 73 (100%) was the reason for avoiding sunscreen use amongst the non-users 73 (24.34%). CONCLUSIONS The prevalence of sunscreen users among medical undergraduate students from our study was higher than other studies conducted in similar settings.