OBJECTIVE: Make an analysis of the factors that influence their survival and prognosis of patients with osteosarcoma treated at a Charity Hospital in Teresina-PI. METHODS: We analyzed medical records of 32 patients diagnosed with osteosarcoma in the period January 2005 to December 2010. RESULTS: Patients were aged between 6 and 73 years, with 56.2% men and 43.7% women. The prevailing color was black, with 62.5% of cases. With regard to histological subtype, the majority were osteoblastic type (71.8%). The anatomical location of the tumor was prevalent region of the knee (distal femur and proximal tibia). Regarding the size of the tumor, tumors were 43.8% bigger than 15 cm. Degree of necrosis Huvos concentrated primarily among the types I and II, 53.1% and 25% respectively. The overall survival at two and four years was 45.5% and 39% respectively and event- free survival at two and four years was 39.8% and 19.9% respectively. CONCLUSION: We considered the worst prognosis, the presence of metastases at diagnosis and tumors larger than 15 cm. And the criteria of Huvos did not reach statistical significance for the prognosis of patients.