BACKGROUND Research on the diagnosis and management of obesity in primary care is limited. Our study goals were to describe the rate of obesity in a primary care setting, to identify factors associated with clinically recognized obesity, and to ascertain the level of diet and exercise counseling for obesity. METHODS Medical records from a private group practice were used for a historical cohort study of 276 patients (aged 40 years and older) who were provided care for a maximum 4.5-year follow-up period. RESULTS Forty-six percent of the study patients (95 percent confidence interval = 0.43, 0.49) received an obesity diagnosis according to medical record notations. The diagnosis of obesity, in turn, was predicted by body mass index (BMI) quartile (P < 0.001) and a positive family history of cardiovascular disease (P < 0.01). Those patients with a diagnosis of obesity had a higher mean level of subsequent weight and diet counseling (P = 0.0001) but the same level (P = 0.11) of exercise counseling as nonobese patients. Weight and diet counseling was also predicted by diabetes (P = 0.0001) and hypercholesterolemia (P = 0.0003). CONCLUSIONS The clinical recognition of obesity was not determined by BMI alone. Although weight and diet counseling was initiated for those individuals described as obese, there was a relatively low level of exercise counseling among these patients. Additional research could provide ways of reducing both physician and patient barriers to exercise counseling.