The 'Lagoa dos Patos' project goal was to assess geological, chemical, physical, biological and socio-economic parameters along the lagoon in order to advise on the best approach for exploration of the Patos Lagoon resources at the time. The Project was composed of monthly expeditions studying distribution and behavior of properties affecting water quality: salinity, water temperature and SPM among other parameters and the dynamics of sediments in the Patos Lagoon, although only Suspended Particulate Matter (SPM) is available here. SPM data were acquired between December 1987 and December 1988 in 19 stations along the lagoon. A total of 13 monthly cruises were carried out from North to South of the lagoon. Stations were located in the navigational canal and samples were obtained at the surface, mid water column, and bottom. All SPM samples were acquired using the methodology by Aminot and Chaussepied (Aminot, A. and Chaussepied, M.: Manuel des Analyses Chimiques en milieu Matin, CNEXO, Bres, p. 396, 1983).