Silicon (SiPcs) phthalocyanines are advantageous because they do not aggregate due to their special structural features. Therefore, they have been widely used in a range of areas in chemical and biological technology. One of the common applications is the use of phthalocyanines on cancer therapies. Pancreas cancer is one of the most common cancers with a high rate of mortality around the world. In this study we therefore aimed to investigate the potential of SiPcs molecules which we previously synthesized for the first time, on increased cell death and the effect on mitochondrial activity in pancreatic cancer cells. The results showed the significantly selective cytotoxic effect of SiPc on cancer cells compared to normal cells. Mitochondrial membrane potential was not different in cancer cells but in normal cells after SiPcs treatment. Pre-incubation time (24h) of SiPcs before light irradiation induced more significant cytotoxicity in pancreatic cancer cells but not in normal cells compared to prolonged pre-incubation (48). This study revisited the biological function of previously synthesized SiPcs, and the results conclude the cytotoxic activity of SiPcs on pancreas cancer. These preliminary findings can be extended for other cancer types and detailed with in vivo models in the future.