Abstract: This invention provides a method for treating cancer in mammals through cellular-organelle-crystallization-induced-death (herein defined as “Cocid”), a method for treating cancer using cellular organelle and/or cytoskeleton crystallizing agents (e.g. tetrazolium salts and their derivatives), pharmaceutical compositions containing a therapeutically effective amount of organelle and/or cytoskeleton crystallizing agents, and compositions containing organelle and/or cytoskeleton crystallizing agents in combination with a pharmaceutically acceptable carrier, diluent or excipient. The crystallizing agents with or without a pharmaceutically acceptable carrier, diluent or excipient, are used in combination with surgery and/or non-surgical anti-tumor treatments.