Tumor necrosis factor alpha (TNF‐α) is a proinflammatory cytokine that is thought to play a role in the pathogenesis of periodontal disease. TNF‐α production is regulated by many factors, including certain alleles of TNF gene polymorphisms. In the present study, TNF genotypes of 3 bi‐allelic polymorphisms were determined in 32 Caucasian patients with adult periodontitis and 32 orally‐healthy matched controls, and correlated with TNF‐α production by oral polymorphonuclear leukocytes (PMN). No differences in distribution of TNF alleles of the −238, −308, or +252 gene polymorphisms were observed between patients and controls or between patients with different disease severity. However, the level of TNF‐α production by oral PMN correlated with the TNF‐α−308 genotype in patients with adult periodontitis, with increased production found in patients with the T1,2 genotype (t‐test; P = 0.037). When cytokine production was examined in patients according to disease severity, an association between the T1,2 genotype and increased production was observed only in patients with advanced disease (t‐test; P = 0.05). These findings suggest that further studies are warranted to determine if the TNF genotype is a risk factor for severity of disease in adult periodontitis. J Periodontol 1998;69:428–433.