Problem: There is limited experience with broad-based use of handheld technologies for clinical care during home visits in sub-Saharan Africa. Objective: We describe the design, development, implementation, and evaluation of a PDA/GPS-based system currently used during home visits in Western Kenya. Results: The system, built on Pendragon Forms, was used to create electronic health records for over 40,000 individuals over a three-month period. Of these, 1900 represented cases where the individual had never received care for the identified condition in an established care facility. On a five-point scale, and compared to paper-and-pen systems, end-users felt that the handheld system was faster (4.4 ± 0.9), easier to use (4.5 ± 0.8), and produced higher quality data (4.7 ± 0.7). Projected over three years to cover two million people, use of the handheld technologies would cost about $0.15 per person - compared to $0.21 per individual encounter entered manually into a computer from a paper form. Conclusion: A PDA/GPS system has been successfully and broadly implemented to support clinical care during home-based visits in a resource-limited setting.