An active surveillance system for contagious bovine pleuropneumonia (CBPP) has been established in Switzerland. The system is based on the detection of typical gross pathological lesions in the lungs of slaughtered cattle, followed by microbiological analysis of the sampled organs and sero-epidemiological investigation of the herd of origin for each suspect case. The programme was tested over six months. The prevalence of lung lesions detected in carcasses during this period in the 108 participating abattoirs was 0.04%, but Mycoplasma mycoides subsp. mycoides SC was not isolated from any of these organs. On the basis of the results presented, there is no evidence of CBPP in Switzerland. The surveillance programme will continue, however, in order to document the situation and eventually obtain a disease-free status in accordance with international standards.