Examination of 150 mentally retarded patients for parasitic infections by urine and stool analysis revealed that 115 (76.67%) were positive. The most prevalent parasites found were T. trichiura in 56%, lumbricoides in 40.6% and duodenale in 21.33%. Double infection was present in 30.67%, triple infection in 15.33% and quadriple infection in 6%. Eosinophilia was detected in 91 (64.08%) of 142 examined cases, all were suffering from intestinal parasites. S. stercoralis was present in 11.33% by stool examination and culture and in 24 (60%) out of 40 examined cases by the IFAT. Toxocara antibodies were present in 38 (56.72%) out of 67 examined cases by the IFAT. Toxoplasma antibodies were present in 106 (74.65%) out of 142 examined cases by the IFAT.