Background: Assessment of individual VTE risk in cancer patients prior to chemotherapy is important. Risk assessment models (RAM) are available but have not been validated for hematological malignancy. We aimed to assess validity of the Vienna Cancer and Thrombosis Study (CATS) score in prediction of VTE in a variety of hematological malignancies. Methods: This is a prospective cohort study conducted on 81 newly diagnosed cancer patients undergoing chemotherapy. Demographic, clinical and cancer related data were collected and patients were followed up for 6 months for VTE events. Khorana score (KS) was calculated. Plasma D-dimer and sP-selectin were measured then V-CATS score was calculated. We assessed modified V-CATS by using new cut off levels of d-dimer and sP-selectin based on ROC curve of the patients’ results. Results: Out of the 81 patients assessed, 2.7% had advanced cancer with metastasis. The most frequent cancer was Non-Hodgkin lymphoma (39.5%) and 8 patients (9.8%) developed VTE events. The calculated probability of VTE occurrence using KS, V-CATS and modified V-CATS scores at cut off levels ≥3 were 87.5%, 87.5%, 100% respectively. The AUC in ROC curve of modified Vienna CATS score showed significant difference when compared to that of V-CATS and KS (P= 0.047 and 0.029, respectively). Conclusion: Our data shows the usefulness of three VTE risk assessment models in hematological malignancies. Modified V-CATS score is more specific compared with V-CATS and KS, while all three scores have similar sensitivity. Implementation of RAM in hematological cancers can help improve the use of thromboprophylaxis.