Background: This is a prospective, observational review of medical records to investigate the associated comorbidities and angiographic anatomy in patients with chronic right bundle branch block(RBBB). Methods: The analyses of 32,345 consecutive electrocardiograms (EKGs) between October 2010 and January 2012 revealed 583 patients with RBBB. The common comorbidities associated with RBBB were hypertension (82%), diabetes (42%), coronary artery disease (CAD) (44%), valvular heart disease (aortic-16% and mitral-17%) and pulmonary disease (33%). Demographic data including age, sex, EKG and associated comorbidities were analyzed from the medical records. Coronary angiograms within 6 months of EKG in patients with RBBB were available for 184 patients and were accordingly analyzed for significant obstructive CAD. Results: In all, 33 patients had single-vessel disease, 52 patients had 2-vessel disease, and 87 patients had multivessel disease whereas 12 patients had no significant disease. Left anterior descending artery was the most frequent vessel involved (72%) followed by left circumflex (58%) and right coronary artery (53%). Conclusions: In conclusion, in chronic RBBB, wherever the angiograms were available, CAD predominantly involved left anterior descending artery. Most common associated comorbidities in chronic RBBB were systemic hypertension and CAD.