The solubility of calcium(II) salts of some salts of bile acids was investigated. Among the considered compounds, the slightly soluble salts were prepared by adding a moderate excess of calcium(II) chloride solution to each solution of the selected sodium bile salts. The obtained solids were analyzed to check their composition and the crystallization water content. Each solid compound was brought in contact at 25 degrees C with an aqueous solution (0.15 or 0.50) mol.dm(-3) NaCl or 0.50 mol.dm(-3) N(CH(3))(4)Cl, as the ionic medium. The obtained suspension was stirred until reaching equilibrium. The equilibrated mixture was analyzed for the free hydrogen ion concentration and for the calcium(II) concentration. Solubility and solubility products were determined for the calcium(II) salts of the following bile salts: cholate, deoxycholate, glycodeoxycholate, ursodeoxycholate, chenodeoxycholate, lithocholate, and dehydrocholate. Calcium(II) glycocholate, taurocholate, and taurodeoxycholate were soluble compounds. The solubility of the investigated salts followed the order: cholate > dehydrocholate > glycodeoxycholate > ursodeoxycholate > chenodeoxycholate > deoxycholate > lithocholate. The solubility in 0.50 mot. dm(-3) NaCl was higher than in 0.15 mol.dm(-3) NaCl, Concerning the contained OH groups the solubility order was the following: trihydroxycholate > dihydroxycholate > monohydroxycholate.