Coronary artery bypass grafting (CABG) is one of the most common surgical procedures performed worldwide. However, its frequent complication, the post-CABG pain (PCP) syndrome, remains poorly documented. This retrospective cohort study was aimed to investigate the prevalence and characteristics of this syndrome. Five hundred and four of 540 subjects, who underwent CABG surgery at our institution between January 1995 and December 1996 and who could be identified, were mailed questionnaires regarding the presence and characteristics of chest wall pain. Eighty of 217 patients, who were defined as having PCP based on these questionnaires, were evaluated in detail. Main outcome measures included a preliminary pain questionnaire, pain localization on a body scheme, a five-point verbal scale and the Visual Analogue Scale (VAS) for measuring pain intensity. Pain qualities, disability and depression were measured by the McGill Pain Questionnaire (MPQ), the Pain Disability Index (PDI), and the Beck Depression Inventory (BDI), respectively. Medical and neurological examinations were also conducted, as well as quantitative thermal testing (QTT) of the chest wall. The preliminary pain questionnaires indicated that 219 of the 387 respondents (56%) reported chest wall pain, which was categorized as PCP. One hundred and forty-two (65%) of the patients with PCP reported pain of at least moderate severity, and 151 (72%) reported that the pain interfered with their daily activities. Eighty PCP patients were available for a detailed evaluation. Left-sided chest wall pain was noted by 53 subjects, midline scar pain by 47, and right-sided pain by nine subjects. Pain intensity (VAS) was 35 +/- 22 (mean +/- SD), MPQ score was 4.9 +/- 3.7, PDI score was 2.0 +/- 0.7, and BDI score was 9.3 +/- 7.3. The neurological examination and the QTT indicated three subcategories of PCP: (1) left-sided chest wall pain often associated with hypoesthesia, mechanical allodynia, and elevated thermal thresholds; (2) midline scar pain accompanied primarily by mechanical allodynia; (3) right-sided, relatively infrequent pain. While the first two subcategories seem to have a neurogenic etiology, this later subcategory of pain is of a mal-defined etiology. This study indicates that PCP is a group of pain syndromes with a high prevalence, and with a negative effect on mood and performance of daily activities. The risk of developing PCP and its potential consequences should therefore be discussed with every patient prior to CABG surgery. These results will need to be confirmed in larger, multi-center studies.