Background: Readmissions are adverse, costly, and potentially preventable. The study aimed to evaluate the cost-effectiveness of reducing readmissions resulting from missed care, depending on the level of education of nurses, from the perspective of the service provider. Methods: We calculated missed care resulting in additional readmissions based on the longitudinal study conducted between 2012 and 2014, as well as readmissions that could have been potentially prevented by adding a 10% increase in hours of nursing care provided by BSN/MSc nurses for 2014. The cost-effectiveness analysis (CEA) was performed to calculate the cost-effectiveness of preventing one hospitalization in non-surgical and surgical wards by increasing the number of nursing hours provided by BSN/MSc nurses. Cost–benefit analysis (CBA) was performed, and the CBR (cost–benefit ratio) and BCR (benefit–cost ratio) were calculated. Results: Increasing the number of hours of nursing care (RN) by 10% decreased the chance for an unplanned readmission by 11%; (OR = 0.89; 95% CI: 0.78−1.01; p = 0.08) in non-surgical wards and 43% (OR = 0.57; 95% CI: 0.49−0.67; p < 0.001) in surgical wards. In non-surgical wards, the number of readmissions that were preventable with extra hours provided by BSN/MSc nurses was 52, and the cost-effectiveness ratio (CER) was USD 226.1. The number of preventable readmissions in surgical wards was 172, and the CER was USD 54.96. In non-surgical wards, the CBR was USD 0.07, while the BCR was USD 1.4. In surgical wards, the CBR was USD 0.02, and the BCR was USD 4.4. Conclusions: The results of these studies broaden the understanding of the relationship among nursing education, patient readmission, and the economic outcomes of hospital care. According to the authors, the proposed intervention has an economic justification. Hence, the authors recommend it for approval by the service provider.