The prevalence rate of Johne's disease in two herds of cattle in Austria was determined using the classical (culture) and a recent technique (PCR). PCR technique based on a 314 bp segment was conducted by using primers complementary to the 18900, insertion sequence specific for M. paratuberculosis. The obtained results revealed that the sensitivity of PCR technique was more or less twice that of cultural technique as the positive results obtained by the first technique were 12.5% while the second technique gave only 6.9% positive results. Sensitivity of the PCR technique in detection of M. paratuberculosis was 100% while it was only 55.6 % for the conventional culture. No positive results were obtained by either test when applied on 33 faecal samples from animals known to be free from Johne's disease, indicating that both are 100% specific. The PCR as compared with the classical culture technique is the simpler, faster and more sensitive with 100% specificity in detection of Mycobacteria.