Serum creatinine concentration is an inadequate screening test for chronic kidney disease, especially in elderly patients. We hypothesized that laboratory reporting of estimated glomerular filtration rate (GFR) accompanied with an educational intervention would improve recognition of chronic kidney disease (CKD). We conducted a before-and-after study at an outpatient family medicine practice. Patients 65 years or older for whom a Cockcroft-Gault GFR could be calculated from their medical record were included. The intervention consisted of automatic reporting of estimated GFR by the hospital laboratory along with an educational intervention directed toward the primary care physicians. The primary outcome was the recognition of CKD (defined as a Cockroft-Gault GFR <60 mL/min [<1.0 mL/s]) by the primary care physician. Factors associated with the recognition of CKD were also determined. The study population comprised 324 patients. Prior to the study intervention, 22.4% of patients with CKD were recognized, which increased to 85.1% after the intervention. Before the intervention, recognition was more likely in male subjects (odds ratio, 4.3; 95% confidence interval, 1.9-9.8) and patients with diabetes (odds ratio, 3.4; 95% confidence interval, 1.6-7.6). These associations were no longer statistically significant after the intervention. Laboratory reporting of estimated GFR coupled with an educational program markedly improves the recognition of CKD in the primary care setting.