Genotypes and allele distributions for the interleukin (IL)-1beta -511 C/T and the IL-1 receptor antagonist gene intron 2 tandem repeat polymorphisms were compared in 206 women with recurrent miscarriage and a control population. No significant differences were observed between the distributions of IL-1beta or IL-1 receptor antagonist gene alleles in either the recurrent miscarriage group as a whole or when divided according to the cause of recurrent miscarriage compared with controls, which suggests that variation in the IL-1 receptor antagonist gene and IL-1beta genes individually does not play a role in susceptibility to recurrent miscarriage.