Bottom grab samples and shallow cores from the Charlotte Harbor system have been studied to show the distribution of its sediments textural and compositional properties. The sediments are relatively uniform in character throughout the harbor system. They are composed essentially of two components, terrigenous quartz sand and biogenic carbonate detritals with minor amounts of phosphorite, kaolinite, montmorillonite, attapulgite, and illite. The terrigenous mineralogical constituents are inherited from adjacent parent rocks and reflect relative availability. The mean grain size of the sediments as well as the percentage of the carbonate detritals increases seaward. The coarse fractions of the sediments are accumulated within high energy areas at the harbor mouth and in the channels, while the finer aggregates are concentrated in the harbor head and lagoons. The distribution of the sediment properties shows that the sediments are shifted by the two major tidal circulations of the harbor proper and of San Carlos Bay. Multivariate nonlinear regression is used to relate the sediment characteristics to their provenance, transportation, and depositional environments.