OBJECTIVE: To evaluate whether primary care physicians document obesity as a diagnosis and formulate a management plan. PATIENTS AND METHODS: The Mayo Clinic primary care database was used to identify general medical examinations performed from November 1, 2004, to October 31, 2005, in a primary care clinic for obese patients (body mass index [BMI] ≥30). Data on demographic variables, BMI, comorbidities, documentation of obesity, and obesity management strategy were obtained through the database. Multivariate logistic regression analyses were conducted to estimate multivariate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: A total of 9827 patients were seen for a general medical examination. Of the 2543 obese patients, 505 (19.9%) had a diagnosis of obesity documented, and 574 (22.6%) had an obesity management plan documented. Older patients (OR, 0.97 per year; 95% CI, 0.96-0.98) and men (OR, 0.60; 95% CI, 0.47-0.76) were significantly less likely to be diagnosed as having obesity, whereas those with a BMI greater than 35 (OR, 2.54; 95% CI, 2.10-3.16), diabetes mellitus (OR, 1.40; 95% CI, 1.09-1.78), and obstructive sleep apnea (OR, 2.34; 95% CI, 1.79-3.07) were significantly more likely to have the diagnosis made. Staff physicians were less likely than residents to document obesity as a diagnosis (OR, 0.55; 95% CI, 0.44-0.69). Diagnosis of obesity was the strongest predictor of formulation of an obesity plan (OR, 2.39; 95% CI, 1.90-3.02). CONCLUSION: Most obese patients did not have a diagnosis of obesity or an obesity management plan made by their primary care physician. Diagnosis of obesity results in a higher chance of formulation of an obesity plan.