We used repeat isoelectric focusing to obtain cytoskeleton proteins of Giardia intestinalis with the characteristics of giardins and tubulins of the ventral disk. Their molecular weight and its variants by pH difference ranged between 30 and 45 kDa. Polypeptides with molecular weights between 97 and 115 kDa were also obtained. Our immunocytochemical studies showed that the proteins with high molecular weight were from the membrane of the trophozoites; in a smaller proportion we observed also proteins with molecular weights similar to those of giardins and tubulins.