Tumour reducing activity of extracts of eight commonly used spices in India were studied in mice transplanted intraperitoneally with Ehrlich ascites tumour. Oral administration of extracts of black pepper, asafoetida, pippali and garlic could increase the percentage of life span in these mice by 64.7%, 52.9%, 47% and 41.1%, respectively. However intraperitoneal administration of spice extracts did not produce any significant reduction in tumour growth except for sesame (38.8%). Garlic extract and asafoetida extracts also inhibited two stage chemical carcinogenesis induced by 7,12 dimethyl benzanthracene and croton oil on mice skin with significant reduction in papiloma formation. These results indicate the potential use of spices as anti-cancer agents as well as anti-tumour promoters.