OBJECTIVE: The goal of this study was to investigate the relationship between plasma levels of insulin-like growth factors-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) and the risk for cervical intraepithelial neoplasia (CIN) and cervical cancer. METHODS: Plasma levels of IGF-1 and IGFBP-3 of 44 cervical cancer patients, 82 CIN patients and 40 neoplasm-free patients were investigated. Then the associations of the plasma levels of IGF-1 and IGFBP-3 with cervical neoplasm or its clinicopathologic parameters were analyzed. RESULTS: The mean IGF-1 concentrations were significantly different among the control, CIN, and cervical cancer groups; the levels were higher in the CIN group compared to the controls. According to the quartile category, the plasma IGF-1 level was significantly higher (p=0.0015) in the CIN group than in the controls. The IGFBP-3 level showed no association between the controls and CIN groups (p=0.842). Although the mean IGF-1/IGFBP-3 molar ratio had borderline significance (p=0.08) among the study population, the quartile comparison showed a significantly higher IGF-1/IGFBP-3 molar ratio in the CIN group compared to the control group (p=0.041). CONCLUSION: Plasma levels of IGF-1 and the IGF-1/IGFBP-3 molar ratio might be useful for the development early detection of cervical lesions and used as an adjuvant diagnostic tool for cervical neoplasia after more larger scale research.