A single nucleotide polymorphism (SNP) is present at position -174 of the human interleukin-6 gene. The risk of developing Hodgkin's lymphoma (HL) in young adults decreases with an increasing number of C alleles at this position. We analysed the effect of this SNP on incidence and outcome in HL. DNA samples from 408 cases and 349 controls were screened and analysed following stratification by age, histological subtype and Epstein-Barr virus status. Although the risk of classical HL in young adults decreased with increasing C alleles, case-control differences were not significant. An excess of G alleles was observed for nodular lymphocyte predominant HL in young adults (n = 21), which was significant.