Celiac disease was diagnosed in one patient with variegate porphyria, and dermatitis herpetiformis in two patients, one with acute intermittent porphyria and the other with erythropoietic protoporphyria. The probability that celiac disease or dermatitis herpetiformis should occur in three patients with porphyria in Finland is less than 0.2%. Neither a consistent HLA pattern nor any other explanation can be offered for the association between these diseases.