Sarcoidosis disease expression differs along racial/ethnic lines and black race has been cited as a poor prognostic factor. Besides genetic, healthcare, and socioeconomic factors, comorbid illnesses may influence sarcoidosis disease expression. We set out to investigate the association between comorbid illnesses and chest radiographic severity in a population of African-American sarcoidosis patients. The study was designed as a retrospective database analysis. The hospital and outpatient databases of the Grady Health System were searched to capture adult patients between November 1999 and December 2003 with the ICD-9 codes of 135 or 519.8, along with all associated secondary and tertiary diagnostic codes. Patient electronic pathology and radiographic reports were reviewed for tissue biopsies showing noncaseating granulomas and for chest radiographic Scadding stage. A total of 165 African-American patients were identified (64% female, 43 +/- 10 years old). Ninety percent (149/165) had comorbid illnesses. The most frequent chronic comorbid illnesses were hypertension (39%), diabetes mellitus (19%), anemia (19%), asthma (15%), gastroesophageal reflux disease (15%), depression (13%), and heart failure (10%). Females had increased frequency and clustering of chronic illnesses. Chest radiographic stages were more severe in patients with anemia, depression, and those less than 40 years old. Males, within each chronic illnesses category, had more severe CXR stages compared to females; however, significance was not achieved. We concluded that most adult patients with sarcoidosis have comorbid illnesses and these, in addition to gender differences, may influence sarcoidosis disease expression. Screening for comorbid illnesses should be an important aspect of sarcoidosis patient management.