A series of 2-(1-hydroxyiminoalkyl)-1,4-dimethoxy-9,10-anthraquinones (oximes) was synthesized and evaluated for cytotoxicity against L1210 cells and A549 cells. These oximes showed a greater cytotoxic activity compared to those of 2-(1-hydroxyalkyl)-1,4-dimethoxy-9,10-anthraquinones as the hydroxyalkyl bioisosteres. The enhanced cytotoxicity assumed to be due to the improved water solubility of the hydroxyimino group. Moreover, it was found that the cytotoxicity of the oximes decreased with elongation of alkyl groups at the side chain. All of the synthesized compounds showed higher cytotoxicity against L1210 cells than A549 cells.