Healthcare is an increasingly collaborative enterprise, involving many individuals and organizations. The ability to provide readily access to integrated healthcare services remotely is now essential. Although Grid technology can support the integration of healthcare services across settings of care and among providers of care, it doesnpsilat make these services available to authorized users at the point of care when needed. The integration of mobile and wireless devices with Grid technology can provide ubiquitous and pervasive access to Grid services. This paper presents HDGPortal, a Grid portal application which provides access to workflow-based healthcare processes using wireless Personal Digital Assistants (PDAs). HDGPortalpsilas architecture is based on wrapping the workflow applications as web services and web service resources. These services are available to users through a number of Grid portal components that can be used for workflow enactment. HDGPortal has been implemented with a multi-layered security infrastructure in order to ensure secure access to healthcare processes.