The SPIRE PACS Parallel Mode Observers' Manual is intended to support astronomers in the definition of their observations using a special mode, where two of the science instruments on board the Herschel Space Observatory are operating simultaneously.

This document is mainly focusing on the description of the Parallel Mode Astronomical Observing Template (AOT) and its optimum use for scientific programmes. Instrument descriptions, scientific capabilities and detailed performance estimations of the two involved instruments are given separately in the SPIRE Observers' Manual and in the PACS Observers' Manual.

This version is written to support the first in-flight Open Time call for Herschel observing proposals by the European Space Agency (ESA) in 2010.