Over the counter (OTC) drugs are drugs easily available without the prescription of a registered medical practitioner (RMP) and self-mediation practices of these drugs are very common in medical students especially in diarrhea which mostly requires dehydration therapy only. But very few reports are available regarding the use of OTC antidiarrhoeal drugs. The aim of the study was designed to assess the practice of self-medication for diarrhea among second year medical students in RIMS, Ranchi, Jharkhand. This was a cross sectional study conducted among medical students in March-April 2017. Data was collected through selfadministered questionnaire and result was expressed as percentage frequency. Questionnaires were filled completely by 224 students out of 269. 81.48% males and 85.07% females were practicing self-medication. Books were the major source of information about drugs and mild nature of illness was the main cause of selfmedication practice. The most common drug group used for diarrhea was oral rehydration salt (ORS) and about 41.07% have used self-medication once in past 6 months. In 75% cases diarrhea was food associated. 41% of the students were against the practice of self-medication. Our study showed that self-medication is widely practiced among medical students and mild nature of illness was the main cause. Educating these medical students regarding the advantages and disadvantages of self-medication is necessary to create awareness among them.