This document is the fifth version of a manual elaborated in the frame of an international project to harmonise the samplings by bottom trawling of the demersal resources in the Mediterranean Sea (MEDITS program). It is the reference document for the surveys to be conducted from 2007 onwards by the research institutes contributing in the Medits surveys on the continental shelves and slopes in the Mediterranean (Fig. 1). The manual describes the sampling gear characteristics, the sampling methodology and the treatment of the samples. Finally it gives the specifications of the data files for data storage and exchange.