Background: Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent liver diseases worldwide. There are several common risk factors between NAFLD and coronary artery disease (CAD). Objectives: This study aims to evaluate the relation between prevalence of NAFLD with severity of CAD in patients undergoing coronary artery angiography. Methods: This study was a cross-sectional descriptive-analysis research that included 514 patients who underwent angiography. The severity of CAD was assessed by the number of vessels involved (vessel score: vd). An ultrasound was performed for all patients and intensity of fatty liver involvement was graded from 0 (absence of steatosis) to 3 (severe steatosis). Results: Ultrasonographic examination proven NAFLD in 59.1% of patients with different grades. Patients with NAFLD had significantly higher body mass index (P < 0.001), waist circumference (P = 0.03), and age (P < 0.001). In addition, there were significant differences between ALT and AST within the normal group and NAFLD patients (P < 0.001). Moreover, coronary angiographic data indicated that the presence of NAFLD significantly correlated with the CAD severity score as so: 64% of people with 2vd and 60.5% of people with 3vd had fatty liver that was statistically significant (df = 4; P = 0.014). Conclusions: This study showed a high prevalence of NAFLD in patients with documented CAD. It is extremely important since knowing risk factors, designing screening programs, and early treatment of fatty liver could led to reducing the risk of cardiovascular diseases.