In 1989, clinical paratuberculosis was detected in the Slovak Republic from two cows on one farm I (out of five farms from one herd) surveyed. Gradually the disease spread to all five farms, designated as I-V containing 1700 cows, 1100 calves and 1300 heifers. The origin of the infection was most probably the importation of 60 heifers of the Holstein breed from Denmark to farm V in the late 70's. In the mid of 80's, due to the common housing of heifers, the remaining four clean herds were also infected with paratuberculosis. In 1990, an eradication and control program against paratuberculosis was commenced. In the first phase (up to 1992), all animals > 18 month old, were tested by three serologic examinations using two different methods. Animals with repeatedly positive serologic results, including the clinically suspected ones were culled from the herd. In the second phase (from 1992) faecal examinations was performed twice a year in addition to serology. Altogether, 15,951 faecal samples were cultured, 30,346 examined by AGID, 20,486 by ELISA and 9,860 by CFT. In the early of 1989-1990, the prevalence of clinical paratuberculosis in farm I-V varied (I-9.4%, II-6.3%, III-0%, IV-0,6% and V-0%). According to the extent of the infection, we divided 366 infected animals into three groups: a) clinically healthy -51.4%, b) clinically healthy with progressive infection -23.5%, c) clinically sick with severe infection - 25.1%. The percentage of culled animals (from 1990-1992) in each category was: a) 22.5%, b) 35.0%, c) 42.5%. Faecal culture, however, revealed that the number of infected animals in group a) increased from 22.5% to 60.0%. Thus, faecal surveillance enabled us to cull individuals which were in the preclinical stage of the disease. Accordingly, the incidence of the disease in 1997 in farm I-IV was < 1.5%. However, in farm V the incidence was still high which could have been due to the common housing of calves with cows between 1993-1996. Our research was partially supported by the Ministry of Agriculture of the Czech Republic (grant no. EP0960006087) and Czech Grant Agency (grants No. 514/95/1594 and 524/97/0948.