The etiology of inflammatory bowel disease is still unknown, but autoimmune phenomena are thought to play an important role. However, only a weak association between HLA or immunoglobulin allotypes and inflammatory bowel diseases has been noted. Recently, DNA markers (restriction fragment length polymorphism (RFLP) pattern) of T-cell receptor gene allotypes have been reported and shown to be linked to susceptibility to autoimmune disease. We investigated the T-cell receptor RFLP pattern in inflammatory bowel diseases. No linkage to the constant region alpha- and beta-chain markers was observed, and no differences in the frequencies of 'genoallotypes' was found between patients and normal blood donors.