In this study, 1,4-naphthoquinone thiazole hybrids were synthesized by reacting 1,4-naphthoquinone thioureas with various α-bromoketones in 78–86 % yields and characterized using 1H NMR, 13C NMR, FT-IR, and HRMS techniques. Furthermore, single crystal x-ray diffraction studies were also performed for 3b and 3c hybrids to determine stereochemistry. Density Functional Theory (DFT) calculations were performed to obtain additional information and to support the x-ray studies. The in vitro anti-proliferative activities of 1,4-naphthoquinone thiazoles were investigated against PC3 human prostate cancer cells. The products 3a–h showed anti-proliferative activity against PC3 cells, and the cell viability studies showed that the IC50 values of compounds 3f and 3e were 20.10 µM and 21.14 µM, respect...