A mobile business process is a special case of a business process where most of the human interaction is done using mobile devices. In this paper, we propose UML-based sup- port for developing such mobile business processes. Here, the business process is first modeled using UML. Then the process model is translated into a BPEL description, which can be run in mobile and/or network-based workflow en- gines. We propose rules to guide modeling of mobile busi- ness processes, to import existing WSDL decriptions into UML models, and to generate executable BPEL descrip- tions with appropriate WSDL definitions. In addition, we introduce our implementation of the approach. The practi- cal applicability is demonstrated by designing a group mes- saging process. It provides a customizable mobile device based communication service offering a business case for mobile operators.