Rh(I) complexes adsorbed on polymers, as a way to Improve their transport and solubility properties, were studied as antitumor agents. The binding constants of the complexes to the polymer were evaluated in order to determine the conditions for maximum association to the vehicle. The toxicity of the pure complexes and those bound were determinedin vivousing female mice. [Rh(NBD)(2,4N))CIO4, complex A; where NBD = norbor-nadlene, (2,4N)=3,3‘-dimethylene-2,2’-di-1,8-nephyridine, was investigated on primary solid tumors and ascltic tumors. [Rh(NBD)(3,4N)]CIO4, complex B; where (3,4N)=3,3′-trimethylene-2,2′-di-1,8-nephthyridine, was investigated on ascltic tumors. These Rh(I) complexes appear to be promising drugs because of their solubility in aqueous polymer, which make them easler to handle in comparison with the neutral species. These complexes show a similarity to clsplatin by reducing tumor growth and by increasing the survival life span of mice. Poly (oxyethylene) was used to solubillze these poorly water-soluble compounds and to stabilize the compounds in the solution before injection. These studies suggest that both complexes, A and B, are good candidates for tumor control growth and increase the survival time.