The indices for the yields evaluation, as well as condition index (CI), that relate the amount of the meat with shell weight are widely used both for scientific research both for shellfish farming management, representing the main tools for the evaluation of merchantable traits in bivalve mollusks. CI values changes are due to a variety of factors, including mainly food availability and physiological status but also animal health and water temperature and salinity. Different methods are used to calculate IC value. in the mussels. The present study is intended to present a simple protocol for the CI mussels (M. galloprovincialis) evaluation able to mediate scientific rigor needs with the management needs in order to adopt an uniform procedure.