Tetratrichomonas didelphidis is a flagellated protozoan found in the intestine of opossums. The specimens were stained by the Giemsa method and by FLUTAX-2, an active fluorescent derivative of Taxol which binds to the ab-tubulin polimerized of microtubules of cells. Giemsa stain revealed the morphological features of trichomonads such as four anterior flagella, undulating membrane, axostyle and posterior flagellum. An intense fluorescence was observed in living trophozoites of T. didelphidis and Trichomonas vaginalis (used as control), incubated with FLUTAX-2. An analysis of the composition of the cytoskeleton of T. didelphidis will contribute to understanding the cellular morphology of the parasites.