Background: Reducing the 30-day readmission is one of the quality performance measures upon which hospitals are being evaluated. Readmissions represent a significant economic burden to the patients and the health care system. Index admission for myocardial infarctions requiring PCI with a concurrent diagnosis of malignancy represents a critical part of the population due to the association between cancer and the pro-thrombotic state that renders them at high risk of readmission. By harnessing the power of large datasets such as the NRD (National Readmission Database), we sought to find associations that, together, could aid in the development of better public and private policies that would make patient care more efficient. Methods: We conducted a retrospective study of the 2017 National Readmission Database (NRD) of adult patients readmitted within 30 days after an index admission for myocardial infarction requiring PCI with a concurrent diagnosis of malignancy. We aimed to identify the 30-day readmission rate, mortality, healthcare-related utilization resources, and independent readmission predictors. Results: A total of 8,350 patients with malignancy underwent PCI. The 30-day readmission rate was 17.8%. The main causes for readmission were sepsis, ventricular fibrillation, recurrent STEMI. Compared to initial admissions, readmitted patients were less likely to require mechanical ventilation (7.3% vs. 5.2%; P = 0.05), intra-aortic balloon pump placement (4.1 vs 0.4; P < 0.01), IMPELLA device use (4.0 vs 0.3; P < 0.01), less had private insurance (16.2% vs 12.9%; P = 0.02), less developed shock (7.7% vs 3.2%; P < 0.01), & less had major bleeding (2.0% vs 0.1%; P < 0.01). Readmission was associated with lower in-hospital mortality rate (1.5% vs. 0.1%; P < 0.01), but more likely to require hemodialysis (4.3% vs 6.6%; P < 0.01), & have venous thromboembolism (VTE) (1.9% vs 3.2%; P < 0.01). The total health care in-hospital economic burden of readmission was $937 million in total charges for patients and $224 million in total costs for hospitals. Independent predictors of readmission were female gender, the disposition to a short-term hospital or skilled nursing facility, prolonged length of stay, inpatient hemodialysis, and VTE episodes. Conclusions: Readmissions after PCI in patients with malignancy are associated with a lower in-hospital mortality rate but pose a high health care burden. We identified potential risk factors that, if targeted, could lead to a reduction in readmissions after PCI in cancer patients, & therefore decrease health care costs.