Compression fractures of vertebrae were noted in 20 out of 1,700 children with the acute lymphoblastic leukemia. Usually prognosis in these cases has been favourable (70% of patients are alive from 5 months to 19 years). Percentage of recovery from compression fractures has been relatively high. Lymphoblastic leukemia with infiltrations localized in the spine is relatively non-aggressive, develops slowly, and despite extensive lesions to the bones its outcome results are favourable. Main symptom of spinal involvement include severe and persisting back aches which make walking impossible. Such symptoms should indicate the diagnosis of leukemia and advocate proper hematological examinations.