Acute diarrhoeal diseases rank second amongst all infectious diseases as a killer in children below 5 years of age worldwide. Globally, 1.3 billion episodes occur annually, with an average of 2-3 episodes per child per year. The important aetiologic agents of diarrhoea and the guidelines for management are discussed. Management of acute diarrhoea is entirely based on clinical presentation of the cases. It includes assessment of the degree of dehydration clinically, rehydration therapy, feeding during diarrhoea, use of antibiotic(s) in selected cases, micronutrient supplementation and use of probiotics. Assessment of the degree of dehydration should be done following the WHO guidelines. Dehydration can be managed with oral rehydration salt (ORS) solution or intravenous fluids. Recently WHO has recommended a hypo-osmolar ORS solution for the treatment of all cases of acute diarrhoea including cholera. Feeding during and after diarrhoea (for at least 2-3 weeks) prevents malnutrition and growth retardation. Antibiotic therapy is not recommended for the treatmentof diarrhoea routinely. Only cases of severe cholera and bloody diarrhoea (presumably shigellosis) should be treated with a suitable antibiotic. Pilot studies in several countries have shown that zinc supplementation during diarrhoea reduces the severity and duration of the disease as well as antidiarrhoeal and antimicrobial use rate. Probiotics may offer a safe intervention in acute infectious diarrhoea to reduce the duration and severity of the illness.