In Switzerland postweaning multisystemic wasting syndrome (PMWS), caused by porcine circovirus type 2, was detected for the first time in 2001. To comprise the PMWS epizooty in 2003 - 2006 retrospectively, individual animals were diagnosed according to internationally accepted criteria and temporal and regional patterns of the epizooty were reconstructed. Occurrence of PMWS was predominantly in regions with a high frequency of swine farms (central and eastern Switzerland). Apparently it was spread to other, less affected regions, through trade of infected fattening pigs. Concurrently, disease was found in different establishments of production. Affected were mainly weaners or fattening pigs. In 40 % of the breeding farms and in 25 % of the fattening farms mortality rate was higher than 5 %. Starting in 2003, also a higher frequency of porcine dermatitis and nephropathy syndrome (PDNS) diseased pigs was diagnosed. In the years 2004 to 2006 they accounted for about 10 % of the diagnosed PCV2-associated diseases. Besides the characteristic skin- and kidney lesions approximately half of the PDNS cases showed wasting and lymphoid lesions with high quantities of PCV2 antigen. We termed these mixed forms PMWS-PDNS-hybrid forms.