The PIH-EMR is a Web based electronic medical record that has been in operation for over four years in Peru supporting the treatment of drug resistant TB. We describe here the types of evaluations that have been performed on the EMR to assess its impact on patient care, reporting, logistics and observational research. Formal studies have been performed on components for drug order entry, drug requirements prediction tools and the use of PDAs to collect bacteriology data. In addition less formal data on the use of the EMR for reporting and research are reviewed. Experience and insights from porting the PIH-EMR to the Philippines, and modifying it to support HIV treatment in Haiti and Rwanda are discussed. We propose that additional data of this sort is valuable in assessing medical information systems especially in resource poor areas.