Endometrial cancer (EC) ranks among the least prevalent gynecological tumors worldwide, with rising incidence due to aging and obesity. Lymph node metastasis remains common in Uterine Corpus Endometrial Carcinoma (UCEC), necessitating new prognostic biomarkers to guide treatment. In this research, UCEC information from the Cancer Genome Atlas (TCGA) was analyzed, and the results were validated using the Gene Expression Omnibus (GEO). Eighteen differentially expressed genetic factors associated with nicotinamide metabolism (NMRDEGs) were identified. Gene Set Enrichment Analysis (GSEA) indicated their role in oxidative stress, hypoxia, glycolysis, and apoptosis processes. Univariate Cox regression identified six key genes (AURKA, CDKN3, FOXM1, CDKN2A, TK1, and CDK1), utilized to progress a hazard prediction framework. Protein-protein interaction (PPI) analysis uncovered additional hub genes such as CDK2, CCNA2, TP53, and FOXM1. The six key genes showed strong prognostic value, and the study's risk model could guide clinical decisions. Nicotinamide metabolism was found to be significantly linked with EC progression. This study offers new perceptions into the role of nicotinamide metabolism in EC and suggests possible avenues for treatment advancements.