Adult cowbirds from the Houston, Texas area were examined for Sarcocystis by three methods. Macroscopically, 53 of 253 (20.9%) birds examined were positive. Microscopic examination of abdominal muscle from 62 of the 200 negative birds showed another 4 (6.4%) to be infected. Pepsin digestion, the most sensitive technique for macroscopically negative birds, showed 7 of the 62 (11.2%) to be infected.