OBJECTIVE: We differentiated women with vulvar vestibulitis syndrome into subgroups on the basis of the time of symptom onset, a history of recurrent vulvovaginal candidiasis, and the interleukin-1 receptor antagonist gene polymorphism. STUDY DESIGN: One hundred sixty-two consecutive patients with strictly defined vulvar vestibulitis syndrome were asked to fill out a questionnaire with the assistance of their gynecologist. A buccal sample was collected from each subject for the analysis of interleukin-1 receptor antagonist gene polymorphism; vaginal and vestibular microbial investigations were performed. RESULTS: Symptoms began with the first act of coitus in 20.4% of patients. A history of a recurrent Candida vulvovaginal infection was reported in 42.6% of patients; 25.9% of the patients were positive for the homozygous interleukin-1 receptor antagonist 2,2 genotype. Women with primary vulvar vestibulitis syndrome differed from women with secondary vulvar vestibulitis syndrome; women with primary vulvar vestibulitis syndrome were younger at the time of the onset of the symptoms (23.8 vs 31.2 years, P <.0001) and had never been pregnant (84.8% vs 61.2%, P <.0001). Women with a history of recurrent Candida vulvovaginitis differed from the other subjects by having a higher frequency of constant vestibular pain (40.6% vs 20.4%, P =.005), a vaginal discharge (79.7% vs 45.2%, P <.0001), and dysuria (62.3% vs 29.0%, P =.0001). Women who were homozygous for interleukin-1 receptor antagonist 2,2 genotype had an earlier onset of symptoms (26 years) than did women who were allele 1 homozygotes (31.3 years, P <.05). They also had a shorter duration of symptoms (4.1 vs 5.9 years, P <.05) and a higher frequency of allergy (47.6% vs 23.4%, P =.002). Human papillomavirus in the vaginal vestibule occurred at a greater frequency in women who were homozygous for interleukin-1 receptor antagonist 2,2 genotype. CONCLUSION: Subgroups of women with vulvar vestibulitis syndrome may be differentiated by symptomatic and genetic variables.