Blastocystis hominis is the most prevalent eukaryotic intestinal protozoa that colonize the human gut, associated with intestinal disorders, with pathogenic controversial as most of them are asymptomatic. In this study, a comparison was carried out for sensitivity and specificity among two common using light microscopy, direct wet smear and Ritchie for the diagnosis B. hominis in human stools. Stool samples were collected from 29 Saudi and 111 non-Saudi patients, and examined for the detection of B. hominis. The infection was among age group between 31-50 years old and the highest rate was among male patients. Also, the results revealed that 98 samples were positive by direct smears; the sensitivity and specificity were 100% &75.9% respectively. Meanwhile, Ritchie technique revealed 86 positive samples, the sensitivity
and specificity were 99% and 90.9% respectively.