Obesity is a known risk factor for diverticulitis. Our objective was to examine the less investigated impact of morbid obesity (MO) on admissions and clinical course of diverticulitis in a US representative database.We retrospectively queried the 2010-2014 Nationwide Readmission Database to compare diverticulitis hospitalizations in 48,651 MO and 841,381 non-obese patients. Outcomes of mortality, clinical course, surgical events, and readmissions were compared using multivariable and propensity-score-matched analyses.The number of MO patients admitted with diverticulitis increased annually from 7570 in 2010 to 11,935 in 2014, while the total number of patients admitted with diverticulitis decreased (p = 0.003). Multivariable analysis demonstrates that MO was associated with increased mortality (adjusted odds ratio [aOR] 1.54; 95% confidence internal [CI]: 1.16, 2.05), intensive care admissions (aOR = 1.92; 95% CI: 1.61, 2.31), emergent surgery (aOR = 1.20; 95% CI: 1.11, 1.30), colectomy (aOR = 1.13; 95% CI: 1.08, 1.18), open laparotomy (aOR = 1.28; 95% CI: 1.21, 1.34), and colostomy (aOR = 1.34; 95% CI: 1.25, 1.43). Additionally, MO was associated with higher risk for multiple readmissions for diverticulitis within 30 days (aOR = 1.45; 95% CI: 1.08, 1.96) and 6 months (aOR = 1.21; 95% CI: 1.03, 1.42). A one-to-one matched propensity-score analysis confirmed our multivariable analysis findings.Analysis of national data demonstrates an increasing trend of MO patients' admissions for diverticulitis, with a presentation at a younger age. Furthermore, MO is associated with an increased risk of adverse outcomes and readmissions of diverticulitis. Future strategies are needed to ameliorate these outcomes.