According to the heterogenous nature of hemolytic uremic syndrome in relation to the etiology, pathophysiology, treatment and diagnosis, we wish to draw attention to the main characteristics about its epidemiological clinical and immunopathological aspects. The HUS's distributes through all the world, but in Argentina, North of Europe, South Africa and west of USA the incidence is higher than the rest of the countries. The immunopathological studies shows thrombotic angiopathic lesion, consisting in generalized alteration of the capillary and arteriolar epithelium. Decreased levels of PGI2, Von Willebrand's factor and bacterial toxins are apparently involved among mechanism that are able to produce HUS. Dialysis is one of the main helps in the treatment of HUS, and in spite of our continued advances in knowledge about this disease, still further developments are needed in pathophysiology and therapeutics to enlight its intimate mechanisms.