fac-[Re(CO)3(L3)(H2O)][NO3] (compound 3),the rhenium(I) tricarbonyl aqua complex, is an anticancer agent associated with mitochondrial dysfunction. fac-[Re(CO)3(L3)(H2O)][NO3] is cytotoxic to prostate cancer cells with IC 50 =0.32 μM (PC-3 cells). fac-[Re(CO)3(L3)(H2O)][NO3] mainly accumulates in mitochondria, down-regulates ATP production in PC3 cells, and promotes paraptosis. However, fac-[Re(CO)3(L3)(H2O)][NO3] did not induce necrosis, apoptosis and autophagy.