Sixty-one novelsteroidal imidazolium salt derivatives were synthesized and evaluated in vitro against a panel of human tumor cell lines. The results showed that diosgenin‒imidazolium salt derivatives displayed much higher cytotoxic activities than cholesterol‒imidazolium salts and dehydroepiandrosterone‒imidazolium salts. The SARs results suggested that the existence of substituted 5,6-dimethyl-benzimidazoles