The TaqI/p12f2 Y-specific RFLP was studied in 258 Italians (69 from North, 74 from Centre-South and 115 from Southern Sardinia) and in 65 Senegalese. The two allelic fragments of 10 and 8 kb characterizing this polymorphism were both found in the Italians but only the 10 kb band was found among the Senegalese. The observed frequency of the 8 kb allele was 32.4% in Central-Southern Italians, 17.4% in Northern Italians and 13.0% in Southern Sardinians. The last figure is significantly lower than that (34.3%) previously reported for a smaller sample of the same population.