Sharks have been claimed to be resistant to cancer and oil from their livers have been used in Scandinavian folk medicine as anti-tumor drug. Shark liver oil contains 40% or more of squalene. Fish liver oil is also rich in squalene and polyunsaturated n-3 fatty acids. The aim of this work was to determine the anti-angiogenic and anti-tumor effects of these substances, together with another Scandinavian traditional remedy--arctic birch ashes--in Balb/c mice after transplantation of syngeneic L-1 sarcoma. All substances tested, alone or in combinations, significantly diminished cutaneous angiogenesis induced by tumor cells, and tumor growth.