Cytologic studies of smears from 130 women suffering from various diseases, including 61 pregnant patients with gestoses, have shown structural changes of the cells in the smears from the endocervix and urethra, that permitted the diagnosis of Mycoplasma infection in 43.8% of patients, Chlamydia infection, 52.3%, and herpes simplex in 72.3% of patients; in 63.9% of patients these infections were combined. Cytologic studies may be useful in the tentative diagnosis of urogenital infections, including cases when it is necessary to elucidate the causes of unfavorable course of a previous pregnancy or when preterm babies are born.