Originally developed as a means for metadata dissemination of preprint and eprint servers, the OAI Protocol for Metadata Harvesting (OAI-PMH) meanwhile has become a widely known solution to connect distributed electronic archives of all kinds. The OAI-PMH owes much of its acceptance not only among experts to its simplicity and the comparatively very low costs of its implementation. After a brief outline of the protocol's genesis and its development to date this tutorial will give an introduction to the main ideas of the OAI-PMH, its general functioning and some protocol details. Then we will deal with special implementation issues for data providers and service providers including both the necessary steps for a local implementation and several examples of freely available and adaptable tools for implementations. The tutorial will also provide an overview of the implementation of a data provider metadata set. Handouts including a glossary of terms will be provided. The tutorial should be attended by persons who are interested in more technical aspects of the OAI Protocol for Metadata Harvesting.