It has been demonstrated that many cytokine genes [e.g. tumour necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10)] show polymorphisms which may affect gene transcription, causing individual variations in cytokine production. The majority of polymorphisms described are single nucleotide polymorphisms (SNPs). In 140 healthy Italian subjects, the allelic and genotype frequencies were determined for the cytokine genes IL-1 alpha (T/C -889), IL-1 alpha (C/T -511, T/C +3962), IL-12 (C/A -1188), interferon (IFN)-gamma (A/T UTR 5644), transforming growth factor (TGF)-alpha (C/T codon 10, G/C codon 25), TNF-alpha (G/A -308, G/A -238), IL-2 (T/G -330, G/T +166), IL-4 (T/G -1098, T/C -590, T/C -33), IL-6 (G/C -174, G/A nt565), IL-10 (G/A -1082, C/T -819, C/A -592), IL-1R (C/T pst11970), IL-1RA (T/C mspa111100) and IL-4RA (G/A +1902). All typings were performed with PCR-SSP assays. Allele and genotype frequencies and linkage disequilibria were calculated and compared with those of other populations.