Objective. To examine the effects of physician specialty and comorbidities on cyclooxygenase 2-selective nonsteroidal antiinflammatory drugs (NSAIDs; coxibs) utilization. Methods. Medical records of 452 patients from a regional managed care organization with ≥3 consecutive NSAID prescriptions from June 1998 to April 2001 were abstracted. Multivariable adjusted associations between coxib initiation and discontinuation and patient and provider characteristics were examined. Results. A total of 1,142 NSAID prescriptions were written over 9,398 total patient-months of followup. Compared with patients seeing family or general practitioners, patients seeing rheumatologists (odds ratio [OR] 3.4, 95% confidence interval [95% CI] 2.1-5.7) and internists (OR 2.3, 95% CI 1.5-3.6) were significantly more likely to receive a coxib, as well as patients with a history of osteoarthritis (OR 2.6, 95% CI 1.7-3.8), gastrointestinal disease (OR 2.3, 95% CI 1.2-4.5), and congestive heart failure (OR 4.1, 95% CI 1.0-16.4). Although specialists were more likely than generalists to prescribe coxibs, only family or general practitioners were significantly more likely to selectively use coxibs among their patients with a history of gastrointestinal disease. Fifty-four percent of NSAID prescriptions were discontinued, and coxibs were significantly less likely to be discontinued than were traditional NSAIDs (OR 0.6, 95% CI 0.5-0.8). Conclusion. Our findings suggest significantly greater, but perhaps less selective use of coxibs among specialists, even after accounting for important covariates. The initiation and discontinuation of coxibs was influenced by physician specialty and by patient risk factors.