Colchicine, desacetylmethylcolchicine and colchiceine suppress the phagocytosis of starch granules by rabbit peritoneal polymorphonuclear leukocytes in vitro. Trimethylcolchicinic acid and 2-desmethylcolchicine glucoside have no effect on phagocytosis. Colchicine, at concentrations as high as 1 X 10(-4) M, has no effect on chemotaxis of polymorphonuclear leukocytes in response to immune complex-activated chemotactic factors or on the motility of these cells. These results do not support the contention that the suppression of phagocytosis or chemotaxis plays a significant role in the anti-inflammatory activity of colchicine.