Structural changes made in breed composition of cattle in the last 30 years in Bulgaria require along with investigations on milk and meat productivity the leather to be studied as strategic raw material. The following breeds of cull cow were studied: ‘Bulgarian black patterned cattle’, 'Montbeliarde' and ‘Simmental’, which had been excluded from breeding for various reasons. Their relative weight, percentage of live leather mass, size, surface and thickness in certain areas were investigated. Sharp differences were found in the relative weight of the leather among dairy breed ‘Bulgarian black patterned cattle’ and combined breeds 'Montbeliarde' and ‘Simmental’ with 6.9 kg for the first and 5.7 kg for the second, or 11.9% and 11.6%, respectively (P<0.05). The best represented in space, as a spreading configuration, are the raw leathers obtained from animals of 'Montbeliarde' breed – 495.36 dm², followed by the those of ‘Simmental’ breed – 437.92 dm² and from ‘Bulgarian black patterned cattle’ – 366.99 dm², or differences of 128.37 dm² and 70.93 dm² (P<0.05). Raw leathers of red-and-white, wide-forehead, combined breeds 'Montbeliarde' and ‘Simmental’ showed higher values of the studied indicators, compared to those obtained from ‘Bulgarian black patterned cattle’.