A series of new dihydroxy- and trihydroxy-9,10-anthracenedione derivatives having N,N-diethylaminopropionamido or N,N-diethylaminoacetamido side chains have been synthesized. The propionamido derivatives inhibit very efficiently turnor cell growth and deserve further testing as potential anticancer drugs. The anthracenedione pharmacophore is very important in cancer chemotherapy; in fact, it belongs to anthracyclines whose outstanding antineoplastic activity is very well documented. Even if anthracyclines still represent the drug of choice for a number of liquid and solid tumors, their use is somewhat limited by the concurrent development of undesired side effects such as bone-marrow depression and cardiac toxicity. In addition, resistance phenomena usually appear following repeated treatment with anthracyclines. To approach a solution for such problems, synthetic anthracenediones were developed, among which Mitoxantrone is clinically used today. Notwithstanding its usefulness, it still exhibits some of the above limitations, including partial cross-resistance with anthracyclines. We and others have recently developed a related class of anthracenediones, with an amido moiety replacing the amino group linking the side chain to the planar tricyclic system. The new compounds exhibited interesting activity in vitro and some of them were also marginally effective in vivo. Besides the presence of two positively charged side chains, the active derivatives were characterized by 1,8-dihydroxy substitution. Together with the nature of the side chain, the number and position of OH groups could also play a relevant role in modulating drug activity. Thus, we deemed it useful to extend our investigation to amido-anthraquinones having hydroxy substituents at different positions of the fused ring system; in particular, in the present paper we report on the synthesis and preliminary biological properties of a number of new 1,4-dihydroxy-5,8-dialkylamido- or 1,4,5-trihydroxy-8-alkylamido-anthracenediones, having N,N-diethylaminopropionamido or N,N-diethylaminoacetamido substituents at position 5,8 or 8 of the anthraquinone structure. The new derivatives allow a direct structural comparison with anthracyclines and Mitoxantrone. In addition, the number and length of side chain substituents were varied to gain information on the requirements for activity in this series of compounds.