Background Our study aimed to assess the burden of obesity on the health system and outcomes in patients with nonvalvular cardiomyopathy. Methods A retrospective analytical cohort, single-center study was conducted at King Abdullah Medical City (KAMC), Makkah, from June 2019 to June 2020, and includes all non-valvular cardiomyopathy (NVCM) patients. The patients were divided into two groups, obese (BMI≥30) and non-obese (BMI<30). The two groups were compared using a t-test and a chi-squared test for continuous and categorical data and regression analysis. Results A single-center, retrospective study was conducted at KAMC, Makkah, and included all NVCM patients (ejection fraction or EF≤45%) who were admitted during this study period. A total of 626 NVCM patients were included in this cohort study; they had a mean BMI of 29±8.1 and a mean EF of 28.4±9.7. Patients were divided into two groups, obese (BMI≥30) and non-obese (BMI<30). Obese patients represented 37% (n=231) of our study population. The non-ischemic category of cardiomyopathy had a higher prevalence among the obese (35% vs 27%). A higher percentage of obese patients presented with heart failure (HF) symptoms rather than ischemia or arrhythmia (46%, 40%, and 7% for HF symptoms, ischemia, and arrhythmia, respectively). There was no significant difference in NVCM complications, including cardiogenic shock, pulmonary edema, and cardiac arrest, between the two groups. Obese patients had a significantly higher post-myocardial infarction (MI) ejection fraction (29.7±9.7 vs 27.5±9.7, p=0.01). We found a statistically significant positive correlation between BMI and length of in-hospital stay (P=0.04). In-hospital mortality was non-significantly different between our two groups, although numerically, it was higher among the non-obese group (obesity paradox) (10% vs 12%, p=0.2). Type of cardiomyopathy, cerebrovascular stroke, smoking, and sacubitril/valsartan intake were detected as independent predictors of in-hospital mortality among our patients. Conclusions Obesity among NVCM patients sets more burden on health facilities by the prolongation of the in-hospital stay of patients although BMI is not an independent predictor of death in those patients.