Background and Objective: Cystinosis is a rare autosomal recessive disorder caused by accumulation of cystine in different organs, Infantile cystinosis characterized by Fanconi syndrome and growth retardation leading to renal failure. The aim of the study was to evaluate the clinical and laboratory findings of cystinotie patients attending at Mofid, Labafinejad hospitals (in Tehran) and Abuzar children's hospital (in Ahvaz), Iran.Subjects and Methods: During 1995-2010, all children with cystinosis hospitalized at the above three centers were enrolled, Patients with the following criteria were considered as cases of cystinosis: i) signs and symptoms of Fanconi syndrome ii) Presence of cystine crystals in cornea using slit lamp.Results: Of all the subjeces, 44 children fulfilled the criteria of nephropathic cystinosis. There were 24 (54.05%) females and 20 (45, 5%) males, Among them, 21 (47.7%) cases were Arabs. The mean age of onset of symptoms was 8 (range 3-18) months. The mean age at the initial presentation of chronic renal failure was 3 years. The most common clinical features in the patients were growth retardation (100%), presence of cystine crystal in cornea (100%), rickets (86%) and polyuria-polydipsia (83%). The commonest laboratory data were glucosuria (100%), renal tubular acidosis (97%), proteinuria (88.5%) and hyposthenuria (82%), Sixteen (36.3%) of the 44 patients received kidney transplant, of which 7 (43.7%) patients rejected their grafts. Finally, 13 (29.5%) of them were relatively good on medical treatment, 8 (18.1%) died, 2 (4.5%) on waiting list of kidney transplantand 21 (47.7%) missed follow up.Conclusion: Although cystinosis is a rare disease in the world, it seems to be a relatively common hereditary disease with unfavorable prognosis in Iranian Arabs.