Recent developments in PDA and networking technologies offer new opportunities for mobile computing. We will investigate these opportunities for the field of transplantation medicine. The Collaborative Transplant Study (CTS) is the largest international voluntary study in this field. More than 300.000 data sets for organ transplantations allow detailed insights into complex transplantation-related issues. For the analysis of this data a multi-tiered web-based statistics application was developed. We suggest scenarios for its mobile use and report on a first field trial. We conclude by proposing a location-based access control mechanism to better protect the highly sensitive transplantation data.