The distribution of PLG phenotypes in the population of Tuscany (Central Italy) has been investigated by means of isoelectric focusing followed by immunofixation of desialyzed sera. In a random sample of 383 unrelated healthy blood donors registered at the Hospital of Pisa, three common phenotypes, PLG A, A-B, and B, and two rare variants were found. The allele frequencies calculated in our study were: PLG*A = 0.6749, PLG*B = 0.3225, and PLG*rare = 0.0026. The theoretical exclusion rate in cases of disputed paternity is 17.42%.