Hemolytic-uremic syndrome (HUS) is defined as a triad of microangiopathic hemolytic anemia, thrombocytopenia and acute renal insufficiency. HUS is one of the most common causes of ARF in childhood. HUS is mainly classified as diarrhea associated and termed typical HUS and atypical HUS (D-HUS), which has no antecedent diarrhea. Familial forms of HUS with autosomal dominant and recessive transmission are known. In adolescents and adults, TTP wherein neurologic features predominate with minimal or no renal insufficiency can occur. Sometimes it may be difficult to distinguish between HUS and TTP and many term it as HUS-TTP syndrome. D+ HUS has been reported from all over the world. There is a peak incidence in the summer months when many epidemics have occurred. It occurs mainly in infants and young children with a slightly higher prevalence in girls.