A great variety of services have been developed to address problems in the field of biomedicine. The EU project Advancing Clinico-Genomics Trials on Cancer (ACGT – http://www.eu-acgt.org) provides a Grid-based platform for improved medical knowledge discovery and integration of biomedical data in clinical trials on cancer. Metadata describing biomedical services needs to be shared to enable discovery and service composition (as workflows). This paper reports a catalogue for knowledge-based discovery of service metadata and a software module to wrap existing command line programs as a secure Grid service able to handle sensitive information.