Background: Breast cancer is the most common cause of cancer in women in the USA after skin cancer. About 264000 cases of breast cancer are diagnosed in women each year in the USA. 42000 women die from this cancer each year. Less is known regarding the association of venous thromboembolism (VTE) in breast cancer. We aim to study the prevalence of VTE in breast cancer and its effect on healthcare utilization using a national database. Methods: We used the National Inpatient Sample (NIS) to collect data for all adult patients >18 years with a diagnosis of breast cancer from 2017-2019 using appropriate ICD 10 codes. These patients were further classified into patients with and without DVT/PE. Multivariate regression analysis was performed to study the effect of DVT/PE in patients with breast cancer taking mortality as primary outcome and total cost and length of hospital stay as secondary outcomes. Results: There were a total of 855494 admissions with a diagnosis of breast cancer. The mean age was 63.87 years and 98.8% of them were females. Acute DVT was found in 1.87% of patients and acute PE was found in 3.01% of patients with breast cancer. A total of 7.36% of breast cancer patients who had acute DVT and 8.04% with acute PE died during the hospital stay. The odds of all-cause mortality for DVT (OR 1.58; 95% CI 1.38-1.82, p<0.001) and PE (OR 1.71, 95% CI 1.52-1.94, p<0.001) were significantly higher in patients with breast cancer than those without. The total cost of hospital stay was 26099 USD ($21814-$30383, p<0.001) higher and LOS was 2.51 days higher (2.22-2.81; P<0.001) when patients developed acute DVT however there was no significant difference in these parameters with PE hospitalizations. Conclusions: Our study concludes that patients with breast cancer who develop acute DVT or PE tend to have worse outcomes in terms of mortality. Length of hospital stay and total hospital charge are also increased in patients developing DVT. Current guidelines (2020) recommend against offering thromboprophylaxis to patients with any cancer. Given the worse outcomes, this study reflects the need to formulate risk assessment models for role of primary thromboprophylaxis in breast cancer.