Ultra low doses used in homeopathic medicines are reported to have healing potential for various diseasesbut their action remains controversial. In this study we have investigated the antitumour and antimetastaticactivity of selected homeopathic medicines against transplanted tumours in mice. It was found that Rutagraveolens 200c and Hydrastis canadensis 200c significantly increased the lifespan of Ehrlich Ascites Carcinomaand Dalton’s Lymphoma Ascites induced tumour-bearing animals by 49.7%, and 69.4% respectively. Moreoverthere was 95.6% and 95.8% reduction of solid tumour volume in Ruta 200c and Hydrastis 200c treated animalson the 31st day after tumour inoculation. Hydrastis 1M given orally significantly inhibited the growth of developedsolid tumours produced by DLA cells and increased the lifespan of tumour bearing animals. Some 9 out of 15animals with developed tumors were completely tumour free after treatment with Hydrastis 1M. Significantanti-metastatic activity was also found in B16F-10 melanoma-bearing animals treated with Thuja1M, Hydrastis1M and Lycopodium1M. This was evident from the inhibition of lung tumour nodule formation, morphologicaland histopathological analysis of lung and decreased levels of γ-GT in serum, a cellular marker of proliferation.These findings support that homeopathic preparations of Ruta and Hydrastis have significant antitumour activity.The mechanism of action of these medicines is not known at present.