This study was conducted to detect prevalence of parasitic infestations in Egyptian chlidren below the age of 5 years and to detect the effect of parasitic infestation on growth and development of these children. This study was conducted on 1900 Egyptian children below the age of 5 years. These children were subjected to clinical examination, complete stool analysis, complete urine analysis and complete blood picture. Some of them were subjected to stool analysis on three consecutive days, urine culture, serology for amebiasis, giardiasis and fascioliasis. Our result showed that the prevalence of parsitic infestation among Egyptian children below the age of 5 years is 67% and about 52% of the infected children were infected with Entrobius vermicularis. Conclusion: parasitic infestation is a common problem in Egyptian children below the age of 5 years