The extent to which a sample of community based, primary care physicians follow current standards of care for the treatment of non-obese, insulin-requiring patients as defined and recently published by the American Diabetes Association (ADA) was studied. A total of 212 physicians responded with 191 indicating that they treat one or more non-obese, insulin-requiring patients. Of this sample, 97% used multiple injection, mixed insulin regimens. However, over 70% also used single injection regimens. Whereas 94% prescribed self-monitoring blood glucose (SMBG), only 31% did so for more than 75% of their patients and 37% did so for less than 50%. Twenty-five percent of respondents did not obtain HbA1 values on their patients. For respondents who do collect HbA1, only 28% did so for over 75% of their patients and 30% for less than 50%. Physicians with fewer patients were more likely to prescribe single injection insulin regimens (P = .02). Recent graduates from medical school also used HbA1's more frequently than earlier graduates (p = .001). These data suggest that while care practices recommended by the ADA are being implemented by primary care physicians, they are significantly underutilized.