Objective: The study is aimed to evaluate the hematological side effects during chemotherapy in a tertiary care hospital. Materials and Methods: This study was a Prospective observational study. The study was conducted at the Oncology Department of Muthoot Healthcare Hospital Pvt Ltd., Kozhencherry, Pathanamthitta, Kerala. A sample size of 200 cancer patients undergoing chemotherapy in the hospital was selected. All subjects were provided with a brief introduction regarding the study and the confidentiality of the data. Relevant information was collected according to the approved pre-designed data collection form. Haematological parameters of the subject was collected to evaluate the myelosuppression. Result: During the study period around 200 cancer patients were found to be admitted in oncology department. The study revealed that all subjects showed haematological side effects. After analyzing the haematological side effects i.e., leukopenia, neutropenia, anemia, thrombocytopenia and lymphocytopenia post tenth day of five cycles of chemotherapy, Grade 1 anemia was found to be more frequent and its incidence increases with chemotherapy whereas other haematological side effects remained at very minimal levels. Conclusion: Cancer is a major concern of current society. By using Common Terminology Criteria for Adverse Events (CTCAE) grade 1 anemia was the most frequently reported haematological side effects. In this study, the effective management of myelosuppression by providing supportive measures like GCSF, whole blood transfusion helped in maintaining the blood counts within normal limits.