This single-center study estimated the significance of pretreatment factors, including comorbidities, which may predict outcome in elderly patients with acute myeloid leukemia and determined how poor risk factors may be used as decision criteria for intensity of chemotherapy in this group of patients. Seventy-seven patients aged ≥ 55 years treated under four different regimens were followed up 36 month. Our results suggest that the most significant predictor for poor overall survival is comorbidity, as scored by the Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI), P = 0.008. The most significant predictor for rate of complete remission is serum lactate dehydrogenase (LDH) level, P = 0.049, and the most significant predictor of early death is leucocytosis, P = 0.007. HCT-CI ≥ 3 was the most significant factor for treatment decision making regarding intensity of chemotherapy. The use of standardized comorbidity assessment tools, such as HCT-CI, for elderly patients with AML is practical and can help to improve treatment decision regarding the intensity of chemotherapy.