Public frequently approach the community pharmacists to answer health-related queries. To provide a quality service, community pharmacists should have updated knowledge on the management of diseases. The present study was aimed to evaluate the knowledge of community pharmacists in the management of diarrhea in adult. Hundred community pharmacists were interviewed using a well-designed peer reviewed ‘Interview Questionnaire Form’. The study result showed that most community pharmacists were not enquiring about the food taken, recent travel, medication history, pregnancy, breast feeding, and associated symptoms before dispensing drug(s) which may leads to wrong diagnosis, drug-drug interaction, toxicity to the foetus, toxicity to the breast feeding babies and ignorance of major health issues. Most community pharmacists were not aware of the basic in treatment of diarrhea which is the replacement of lost electrolytes and fluids during diarrhea. Few community pharmacists were not recommending the patients to seek expert opinion in severe cases of diarrhea. Most community pharmacists were not counselling the patients regarding the complication of dehydration and its prevention using oral rehydration powder; how to reconstitute oral rehydration powder; importance of personal hygiene, basic sanitation and good drinking water and when to seek expert opinion. The study concludes that most community pharmacists in and around Bhavani and Komarapallayam were not adequately knowledged to provide a quality service in the management of diarrhea in adults. Pharmacy colleges and physicians should take the responsibility of educating the community pharmacists through regular refresher programmes on various health related issues.