Two hundred and seventy buffalo's oesophagus muscle samples collected from Giza abattoir were examined macroscopically and microscopically for the presence Sarcocystis. The results indicate the presence of macroscopic Sarcocystis fusiformis at the rate 88.9% and microscopic Sarcocystis at the rate of 85.5% by the compressorium method and 93.3% by the use of tyrosine digestion technique. The incidence of infection with both species was 93%. The morphological features of the demonstrated Sarcocystis species and the liberated merozoites were described. At the same time blood samples were taken from the same animals and sera were separated for the estimation of total protein, urea, uric acid, calcium, inorganic phosphorus and magnesium levels together with alkaline phosphatase and alanine amino-transpherase activities. The results indicate significant decrease in total protein level and significant increase in both alkaline phosphatase and ALT activities. Minor insignificant changes were observed in the other investigated parameters.