We set a method targeting 16 rRNA gene consisting in a single polymerase chain reaction of 40 cycles which is specific for pathogenic leptospira. Negative polymerase chain reaction results were observed with nonpathogenic Leptospira (serovar patoc) and other bacteria species. By this method a survey on a population of autochthon swine herds had been conducted in Sicily particularly on kidney samples of slaughtered animals and on urine samples from live animals. The analysis showed that a prevalence of leptospira up to 40 % can be observed on these animals. Results on other bovine and ovine herds from the same province in Sicily showed a lower prevalence.