OBJECTIVES: Describe the perioperative characteristics of the patients undergoing coronary artery bypass grafting (CABG) in San Juan, Veterans Affairs Medical Center (SJ-VAMC). Determine the in-hospital and 30-day morbidity and mortality following CABG and identify adverse predictors for postoperative complications. BACKGROUND: Preoperative risk factors for complications post-CABG have been identified; however limited data is available regarding the value of these predictors in the Puerto Rican Population. METHODS: Perioperative characteristics and 30-day complications were gathered from all patients undergoing CABG (n = 252) at the SJ-VAMC (2001-2003). Logistic regression analysis was performed to determine factors associated with the occurrence of complications. RESULTS: The population's mean age was 66.9 +/- 8.1 years. Associated illnesses included: hypertension (95.6%), diabetes (57%), past smoking (61%), COPD (26%), chronic renal insufficiency (CRI-11.5%), cerebrovascular disease (CVD-20.6%), disabling angina (78%), 3-vessel coronary disease (75.8%), significant left main stenosis (20%), and non-elective surgical intervention (54%). The most frequent primary complications were postoperative myocardial infarction (MI-4.8%) and congestive heart failure (4.8%). The 30-day mortality was 1.2%. Upon multivariate analysis PRBC transfusions > 3 units was associated to increased risks of primary complications, in patients with prior history of CVD. CRI and LVEF < or = 40% were independently associated to development of primary complications, in patients with prior MI and CVD. CONCLUSION: The preoperative characteristics are suggestive of an older and sicker patient that is undergoing CABG at the SJ-VAMC. Despite this, the death rate was low and the frequency of other complications comparable to the Society of Thoracic Surgeons (STS) National Adult Cardiac Database.