The present invention relates to bile acid or bile salt fatty acid conjugates (hereinafter called "BAFAC), to their use in dissolving cholesterol gallstones in bile, preventing their occurrence or recurrence, to their use in reducing or preventing arteriosclerosis and to methods for the treatment of said diseases. The conjugates are of the formula W-X-G in which G is a bile acid or bile salt radical, W stands for one or two saturated fatty acid radicals and X is either a direct bond or a bonding member between bile acid or bile salt and the fatty acid(s). The conjugation is advantageously performed at a position selected among the 3, 6, 7, 12 and 24 positions of the bile acid or bile salt nucleus. The fatty acids are preferably saturated fatty acids having 6-26 carbon atoms.