Objective: This study aimed to to evaluate the variation and importance of certain hematological, enzymatic, and oxidative stress markers in women with breast cancer under chemotherapy treatment. Methods: The study comprised forty histopathologically proven female breast cancer patients at Omega Cancer Hospital in Visakhapatnam. All subjects were divided into four groups: a control group of 40 healthy females of similar age, a group of 40 breast cancer patients (before chemotherapy, during chemotherapy, and after chemotherapy), and all subjects were undergoing treatment with anticancer agents. Results: During chemotherapy, lipid peroxidation and Nitric oxide (NO) levels were significantly increased in AC-treated breast cancer patients than in controls. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were non-significant increase in treatment group than controls. Whereas biochemical profiles, were decreased in treatment group than controls. In AC-treated breast cancer patients, Hematological profiles were found significantly reduced than in controls. Conclusion: Chemotherapy causes a certain amount of systemic oxidative stress, which persists during subsequent clinical interventions and may influence the patients' clinical outcomes. Chemotherapy produced significant adverse effects such as anaemia, neutropenia, leukopenia, thrombocytopenia, and hepatic dysfunction as a side effect of treatment due to disturbed and lowered levels of haematological parameters.breast cancer