Background: In the evaluation of patients with suspected coronary artery disease (CAD), the role of non-invasive imaging has increased exponentially over the past decades. Objective: To assess the diagnostic value of coronary computed tomography angiography (CTA) and stress single photon emission computed tomography (SPECT) in evaluation of chest pain in diabetic and non-diabetic patients. Patients and Methods: This study included 150 patients with chest pain suggestive of coronary artery disease seen in outpatient cardiology clinic at Al-Hussein and Bab-Elshareia University Hospitals. The study was carried during the period from April 2019 till January 2021. Patients underwent coronary angiography (CA). Patients randomly included 100 diabetic patients and 50 nondiabetic patients. All patients were examined with ECG, echocardiography, 64-slice computed tomography (CT) scanner and ECG gated SPECT. Results: Positive CTA and CA significantly increased in diabetic group than non-diabetic group (P = 0.005 and 0.014). There was an insignificant difference (good agreement) between CA and CTA (P = 0.001). There was a significant difference (bad agreement) between SPECT and CA (P = 0.001). Conclusions: In both patients with diabetes mellitus (DM) and without DM, CTA had a good agreement with the results of CA unlike SPECT. Positive CA and CTA were more common with DM.