Epidemiological studies have showed that low levels of antioxidants induce the generation of free radicals leading to DNA damage and further mutations seen in cancer. This study evaluated the effects of oxidative markers on the occurrence and severity of cervical cancer at the Lagos University Teaching Hospital. This was an analytical cross-sectional study carried out among women with histological diagnosis of invasive cervical cancer and their healthy cancer-free comparison group. Venous blood samples were collected from each participant for measurements of antioxidants (erythrocyte glutathione and vitamin C) and malondialdehyde (a marker of lipid peroxidation). Descriptive statistics were carried out for relevant demographic and clinical data. Associations between continuous variables were tested using the independent sample t-test or the analysis of variance for normally distributed data or the Mann–Whitney U test for skewed data, whereas categorical variables were compared using the χ2 test. p < 0.05 was considered statistically significant. The mean level of malondialdehyde (MDA) was statistically higher in women with cervical cancer than in their cancer-free counterparts (p = 0.032). However, the mean glutathione (32.6 ± 6.2 versus 14.2 ± 6.1 mg/dL; p = 0.019) and vitamin C (12.4 ± 2.3 versus 14.6 ± 2.4 µmol/L; p = 0.001) levels were significantly lower in the case group compared to the cancer-free group. There are statistically increasing mean levels of MDA (p = 0.017) and decreasing mean levels of vitamin C (p = 0.004) with increasing stages of the disease. This study showed that women with cervical cancer have low levels of antioxidants and an increased level of the oxidative marker. The levels of these markers become more pronounced as the disease progresses. This will, therefore, form the basis for the conduct of future randomised controlled trials of antioxidant supplementations among cervical cancer patients in sub-Saharan Africa.