The objective to this retrospective study of 341 cases of primary carcinoma of vagina (PCV) diagnosed between 1956 and 1996 was to find whether epidemiological, clinical, and histopathological variables were related to the age at diagnosis of patients with PCV. The univariate statistical analysis showed that younger age at diagnosis significantly correlated with a history of cervical dysplasia, hysterectomy, gynecological infections, and tumors located in the upper part of the vagina, whereas older age at diagnosis significantly correlated with late menarche and exophytically growing tumors. In the multivariate regression analysis, the remaining independent predictors were a history of cervical dysplasia and age at menarche. Further, parity >/=4 as well as nulliparity, smoking, and unstable marital status were more common among patients with PCV than among those in the general Swedish female population. This study indicates that the etiology of vaginal carcinoma may be age related. In young patients, the disease seems to be etiologically related to cervical neoplasia and thus human papillomavirus (HPV) dependent. However, in the most common age group, the older patients, there might be another (probably non-HPV-related) etiology associated with hormonal factors and trauma to the vagina.