Background: Causes of blindness in children vary according to the region and socioeconomic development. Within a given country these causes vary with passage of time. This reflects different levels of socioeconomic development and provision of healthcare services. This cross-sectional study was undertaken to estimate the major causes of severe visual impairment in children and specially preventable and curable blindness in southernIran. Methods: 145 students of Shiraz Blinds' School,Shiraz,Iran, interviewed, examined and their medical documents reviewed. Causes of visual loss were analyzed according to involved anatomic area. Results: 145 students (290 eyes) were examined (53.1% girls and 46.9% boys), among which 42.1% had vision of no light perception. Eye dysgenesis was found in 21.4%, glaucoma in 15.9%, lens associated visual loss in 6.2%,  optic nerve lesions in1.4%, retinal problems in 54.48% and corneal problems in less than 1%. Sixty five students had retinitis pigmentosa, which was the single commonest cause of visual loss. Conclusion: The major cause of childhood blindness in this region is retinitis pigmentosa, followed by microphtalmia, eye dysgenesis and congenital glaucoma. Large proportion of these blind children had a positive history of consanguineous marriage in their parents and this seemed to be the most probable cause of increased frequency of genetic causes of childhood blindness.Iran J Med Sci 2005; 30(2): 55-58. Keywords ● Childhood Blindness ● retinitis pigmentosa ● consanguinity