Trichinosis is an infection contracted by ingestion of meat containing viable larvae of the nematode Trichinella spiralis. This report concerns an outbreak of infections with this parasite in Navarra, Spain that was associated with home-prepared pork products. After the detection of a person with trichinosis, a study of all subjects that had ingested meat from the presumably infected pork was carried out. Forty-four members of eight families were enrolled in the study. Ten had symptoms suggestive of trichinosis, 20 had hypereosinophilia, and 15 had positive serologic test results for anti-Trichinella antibodies. Three groups could be distinguished according to the kind of product each subject had ingested (pork sausage, blood pudding, and loin). Twelve months later, all had a normal eosinophil count and a negative serology.