Cisplatin is a chemotherapy drug effective against several forms of cancer, but can also cause serious side-effects, including nephrotoxicity and ototoxicity. Curcumin, a natural plant compound, can increase cisplatin’s anti-cancer activity and counteract cisplatin’s deleterious effect on the auditory and renal systems. Unfortunately, curcumin exhibits poor bioavailability, which has promoted interest in the development of synthetic curcumin analogs (curcuminoids) that are soluble, target cancer, and do not cause side effects. This study investigated whether the curcuminoid (3E,5E)-3,5-bis[(2-fluorophenyl) methylene]-4-piperidinone (EF-24) increases the anti-cancer effects of cisplatin against a human ovarian cancer cell line (A2780) and its cisplatin-resistant counterpart (A2780cis), while preventing cisplatin-mediated side effects in a human kidney cell line (HEK-293T) and a mouse auditory hybridoma cell line (HEI-OC1). The effect of cisplatin and EF-24 on cellular viability was measured using the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. The expression and activity of signal transduction proteins in several apoptotic pathways was measured using caspase luminescence assays. Reactive oxygen species (ROS) production was also measured using flow cytometry. Our data suggest that cisplatin and EF-24 are effective against ovarian cancer cell lines, but both compounds may also have adverse effects on auditory and renal cells. This project provides relevant information that may improve our understanding of how these compounds function in different tissues, facilitating improved cancer treatment and circumvention of side effects commonly associated with cisplatin treatment.