Abstract: The skeletal muscle or meat is the most often eaten part of beef and may have some Sarcocystis cysts. Most portion of raw hamburger (about 70%) is made of meat. A study was made on 80 raw hamburger samples collected from retail food stores in Garmsar; Iran, for detection of Sarcocystis cysts by histological method. A total of 400 haematoxylin and eosin-stained tissue samples prepared from these 80 hamburgers were examined for the presence of Sarcocystis. Sarcocystis cysts were detected in five of the 80 hamburger examined. Therefore, the prevalence rate of Sarcocystis cysts in meat of hamburger was 6.25%. The Sarcocystis cysts contained numerous merozoites. Merozoites stained blue color and they have been detected from muscle tissues which stained red color. Some photomicrographs showed more than one cyst at a microscopy field and they had various size. The sizes of cysts were 8.4 to 39.2 x 14 to 75.6 μm.