The relationship between the blood supply of the papillary muscles of the left ventricle of 90 adult human Caucasian hearts and the arteries of the cardiac anatomicosurgical segments was studied after arterial injection of Vinyl acetate and partial or total corrosion. The anterior papillary muscle belongs in most cases to the I SV segment whereas the posterior muscle belongs to the III DV segment, the former pertaining to the left coronary a. and the latter to the right a.