In this study, some of the synthetic curcuminoid derivatives are analyzed for their anti-angiogenic activity. Intraperitoneal administration of the compounds tetrahydrocurcumin (THC), salicyl curcumin (SC) and curcuminIII (C-III) reduced the number of tumour directed capillaries induced by injecting B16F-10 melanoma cells on the ventral side of C57BL/6 mice. THC (14.5 +/- 2.5 capillaries) and SC (16 +/- 2.5 capillaries) were more significant (P < 0.001) than C-III (19 +/- 1.8 capillaries) compared to the untreated control (30.8 +/- 2.1 capillaries). Treatment with these curcuminoids reduced the serum NO as well as TNF-alpha levels of the angiogenesis-induced animals. In vitro NO and TNF-alpha production by the activated MOs were reduced in a concentration dependent manner by the treatment of the curcuminoid compounds.