Cervical and ovarian cancer are two aggressive neoplasms for women, still with high mortality and morbidity. Among the molecules and compounds that have anticancer activity, it was studied the JG-98, a heat shock protein 70 (HSP70) inhibitor. It demonstrated inhibitory effects on the growth of neoplastic cells, mediated by the induction of apoptosis, with anti-proliferation activity on neoplastic cells via the apoptotic pathway. The authors investigated the antiproliferative effects of JG-98 on human cervical cancer HeLa and ovarian cancer SKOV-3, examined by a standard XTT assay. Apoptotic effects and oxidative status were also evaluated by flow cytometry, ELISA, and total oxidant status assays in HeLa cells, respectively. The IC50 values of JG-98 in HeLa and SKOV-3 cells were recorded as 1.79 and 2.96 μM, respectively. Flow cytometry results showed that JG-98 treatment remarkably increased the proportion of apoptotic cells at IC50 concentration. The JG-98 treatment significantly increased the proteins Bax, cleaved caspase 3, cleaved PARP, and 8-oxo-dG levels, all indicators of cellular apoptosis. These findings show that JG-98 significantly decreased cell proliferation and increased apoptosis in HeLa cells, suggesting that JG-98 has a promising anti-tumor effect in cervical and ovarian cancers.