Hypovolemia is common among surgical, trauma, and intensive care unit patients. It can occur in the absence of obvious fluid loss secondary to vasodilatation or during generalized alterations of the endothelial barrier resulting in increased capillary permeability. Hydroxyethyl starch solutions are increasingly used for the volume replacement therapy. Hydroxyethyl starch solutions are synthetic colloids with the pharmacological properties that are the closest to natural colloids. Important characteristics for these products are molecular weight, their concentration, the degree of molar substitution, and the substitution pattern. In this review article a large variety of hydroxyethyl starch solutions, their physical and chemical characteristics, pharmacokinetics and metabolism, the main route of elimination, mechanism of action, effect on blood plasma volume, safety, tolerability and side effects (the risk of adverse effects on hemostasis, platelet function, frequency of pruritus, anaphylactoid reaction, incidence of rise in serum amylase) are presented.