We have studied the influence of hydropinic treatment with calcic and magnesic-sulphate-sulphurous spring mineral water (IDCS water) on plasma cholesterol (T-Ch), low density lipoprotein (LDL-Ch) and high density lipoprotein (HDL-Ch) levels, in experimental animals made hypercholesterolemic with a high cholesterol diet, and investigated possible mechanisms involved in lipoprotein metabolism.Ad libitum intake of IDCS water, during the 120 days of a hypercholesterolemic diet, produced an increase in the T-Ch/LDL-Ch ratio, compared to that of hypercholesterolemic animals treated with tap water. This datum indicates that after treatment with spring mineral water the LDL-Ch plasma concentration increases less than that of T-Ch. Vice versa, the T-Ch/HDL-Ch ratio was lower. Considering that the HDL-Ch levels in hypercholesterolemic rats treated with IDCS water were not significantly different than those of control animals, the very low T-Ch/HDL-Ch ratio recorded indicates that IDCS water intake during a hypercholesterolemic diet induces a lower increase of the T-Ch and LDL-Ch levels by increasing lipoprotein metabolism, which leads to reduced bile acid absorption both through precipitation in the intestinal lumen and increased excretion via the feces.