In a prospective study, risk factors of the development of cervical carcinoma in 210 diseased and 100 healthy subjects were investigated. Special attention was paid to metaplastic changes in the portio vaginalis cervics and to human papilloma virus which are considered responsible for the development of these changes. It has been found that metaplasias are favoured by adolescence, chronic irritative processes in the cervix (pathologic discharge recorded in 51.9% of the diseased and 38% of the healthy), cervical lacerations (33.8%:9%), and a prolonged use of hormonal contraception (37.1:15%), all relationships being statistically significant. The factors statistically significant for the development of infection with human papilloma virus proved to be early sexual life (16.2% of the diseased and 6% of the healthy), a great many changes in sexual partners (6.7%:1%), unreliable sexual devotion of the male partner (56.2%:42%), the use of non-barrier contraception methods, and inadequate sexual hygiene. It has not been found that some other factors (profession, number of marriages, nationality, and the like) have an important effect on cervical changes.