This study was performed between 2007-2012 and encompasses 94 patients. The patients were divided in two groups. The first group included the patients who have benefited from surgical treatment (42 cases) and the second one included patients who benefited from conservative treatment. Out of the total number of cases, 63 cases showed an intact simple bone cyst that was most of the time an accidental discovery. 31 patients presented with fracture sustained on a simple bone cyst. There were 63 boys and 31 girls. Their mean age was 9.9 +/- 2.34 years. Single injection was performed for 49 patients; the rest had double or triple injections. The mean follow-up was 34.5 +/- 6.6 months. The procedure succeeded in obtaining healing in 77 cysts (82%). Cyst index of more than five and cortical index of less than 1 mm were significantly prone to pathological fractures and had significant poor results after treatment. Our results suggested that an autogenous bone marrow injection is a safe and effective treatment method for simple bone cysts, when compared with the surgical management, but sometimes-repeated injections are necessary. Cyst index and cortical width are good indicators for treatment outcome.