Background: Utilizing geriatric screening tools for the identification of vulnerable older patients with cancer is important. The aim of this study is to evaluate the hospitalization risk of elderly hematologic cancer patients based on geriatric assessment and laboratory parameters. Materials and Methods: In this cross sectional study 61 patients with hematologic malignancies, age 65 years and older, were assessed at a hematology outpatient clinic. Standard geriatric screening tests; activities of daily living (ADL), instrumental activities of daily living (IADL), Mini Nutritional Assessment (MNA), Mini Mental State Examination (MMSE), timed up and go test (TUG), geriatrics depression scale (GDS) were administered. Demographic and medical data were obtained from patient medical records. The number of hospitalizations in the following six months was then recorded to allow analysis of associations with geriatric assessment tools and laboratory parameters. Results: The median age of the patients, 37 being males, was 66 years. Positive TUG test and declined ADL was found as significant risk factors for hospitalization (p=0.028 and p=0.015 respectively). Correlations of hospitalization with thrombocytopenia, vitamin B12 and folic acid deficiency were statistically significant (p=0.004, p=0.011 and p=0.05 respectively). Conclusions: In this study, geriatric conditions which are usually unrecognized in a regular oncology office visit were identified. Our study indicates TUG and ADL might be use as predictive tests for hospitalization in elderly oncology populations. Also thrombocytopenia, and vitamin B12 and folic acid deficiencies are among the risk factors for hospitalization. The importance of vitamin B12 and folic acid vitamin replacement should not be underestimated in this population.