SETTING: The State of Alabama Department of Public Health Division of Tuberculosis Control. OBJECTIVE: To standardize contact investigation protocols and implement an intervention to increase TB field worker adherence to the protocols with the goal of promoting efficiency and effectiveness in contact investigations. DESIGN: A process evaluation of existing data collection and management systems and protocols was performed. Standardized protocols and an intervention to increase TB field worker adherence to the protocols were created and pilot tested. These were then implemented and formative evaluation data were collected. RESULTS: The process evaluation revealed considerable variance among field workers with regard to protocols and definitions of variables related to contact investigations. Protocols were standardized and an intervention targeted at TB field workers was developed. The intervention consisted of a training workshop and the development of a computer-based contact investigation module. This was successfully implemented throughout the state. CONCLUSIONS: To perform effective contact investigations and conduct studies to improve the effectiveness of these investigations, TB control programs must pay careful attention to precisely defining variables and concepts related to the contact investigation. Furthermore, protocols must be standardized and resources devoted to training of TB field workers to ensure adherence to protocols.