Low levels of adherence to self-monitoring of blood glucose continue to occur despite its importance in the self-management of diabetes. Currently developed scales measure barriers to all components of diabetes regimen adherence but include only a few items about blood glucose testing. The purpose of this study was to develop the Barriers to Self-Monitoring Blood Glucose Scale and examine its psychometric properties. Data were drawn from two large diabetes clinics affiliated with large metropolitan hospitals. The 80-item scale examined the circumstances, thoughts, and feelings associated with barriers to testing blood glucose. Results suggest that individuals who test less often are more likely to report a higher numher of barriers. This scale provides a means fon assessing multiple barriers to testing that can provide the basis for healthcare practitioners to design individualized interventions to increase adherence to testing.