Development and implementation of a protocol for identifying and treating depressed patients in a busy, group model, HMO primary care practice is described. Initial results and barriers to implementation are reported. A simple depression screening tool was adapted and a protocol for using available primary care staff and resources was developed to efficiently integrate screening and treatment for depression into daily practice. Important components of the program included specification of the target population, adaptation of a patient self-report diagnostic and rating tool, a nurse-educator protocol for patient follow-up and telephone support, a database to track patient progress, training for primary care staff, and collaboration with specialty Behavioral Health Care. After piloting, plans were made for transferring the model to other practices. Although the protocol was seen as beneficial to the PCP, Nurses, and patients involved, the scarcity of resources in other primary care practices proved a major barrier to full implementation.