The presence of HPV, using the Digene Hybrid Capture System, was identified in a group of 324 women with CIN and in 228 women with normal cytological smears. Risk of occurrence of CIN was 40 times higher for high risk HPV types. The serum folic acid level and the level of antioxidant compounds in plasma (retinol, alpha-tocopherol, vitamins C and E) in women of the studied and control group was determined by HPLC (high-performance liquid chromatography-reversed phase). Statistically lower levels of folic acid were found in the women with CIN-HPV (+) (OR: 7.5: 95% CI: 1.2-9.7). Studies have shown that lower levels of antioxidants coexisting with low levels of folic acid increases the risk of CIN development.