Hydroethyl starch (HES) represents the latest generation of artificial colloids following gelatin and dextran. Concentration is usually expressed as percentage which denotes that higher the concentration, higher the volume expansion effect. 6% HES solutions are iso-oncotic in vivo, with 1:1 replacement of blood loss, 10% solutions are hyperoncotic, with a volume effect considerably exceeding the infused volume (about 145%). The duration and extent of plasma expansion are extremely dependent on the physical and chemical characteristic of the HES solution. Different HES preparations cause different effects and side-effects. Highly molar substituted HES preparations are associated with considerable derangement effects on blood clotting, platelet function and subsequently increased post-operative bleeding. The degree of accumulation is highly dependent on the type of HES used for volume replacement. The effects on renal function are more prominent with high degree of substitution of HES, with high dose and least with tetrastarch. HES are associated with higher incidence of anaphylactoid reactions as compared to other synthetic colloids as well as albumin. The clinical uses and advantages, disadvantages, the indications, contraindications, and the dosage of each of them have been described here.