OBJECTIVE:: Estrogen metabolites have been associated in the pathogenesis of breast and cervical cancer; 16α-hydroxyestrone(16α-OHE1) demonstrated proliferative effects whereas 2-hydroxyestrone(2-OHE1) had antiproliferative effects. Our study's objective is to demonstrate that head and neck (H & N) cancer patients metabolize estrogen differently than healthy controls, which may constitute a risk factor for H & N cancer development. STUDY DESIGN:: Urinary metabolite levels of 2-OHE1 and 16α-OHE1 from 50 H & N cancer patients and 50 age- and sex-matched controls were measured using enzyme-linked immunosorbent assay (ELISA). Absolute values and 2-/16α-OHE1 ratios were calculated. Conditional logistic regression for univariate and multivariate analysis with odds ratio (OR) and 95% confidence interval (CI) were used. RESULTS:: Thirty percent (15 of 50) from the case group had a low 2-/16α-OHE1 ratio compared with only 4% (2 of 50) in the control group (OR = 11.1; 1.4-91.5, 95% CI) (P < 0.05). When adjusted for tobacco, OR remained significant at 15.6 (1.1-212.5, 95% CI) (P < 0.05). CONCLUSION:: H & N cancer patients are more likely to express abnormal estrogen metabolism than healthy controls; 2-/16α-OHE1 may serve as a potential biological marker of individuals at increased risk of H & N cancer. (Otolaryngol Head Neck Surg 2001;124:241-7.)