The macrofaunal community structure and the secondary production of Excirolana armata, Euzonus furciferus, Scolelepis squamata, Mellita quinquiesperforata and Callichirus major were studied from February 1992 to March 1993, in a southern Brazil sandy beach. Sampling stations were distributed throughout a transect of 270 m, from the upper sub-aerial beach to nearly 3 m deep, in the sub-aqueous beach. Three biological samples of 0.05 m2 and 20 cm deep were obtained in each station and sieved through a 0,5 mm mesh. The beach presented a modal dissipative morphodynamic state, with a gentle slope (about 1o), and sediment composed of fine to very fine sands, with an average of 2.90 f in the beach face. Macrofaunal abundance showed a clear seasonal variation, with highest values occurring during winter for intertidal stations and during spring for subtidal stations. From the 61 taxa identified five species were responsible for 69% of the individuals and more than 90 % of the biomass. E. armata showed a life span of 1.2 years for males and 1.9 years for females, with a secondary production of 0.351 gAFDW m-2 year-1 and a P/B ratio of 1.86 year-1. E. furciferus had a life span of 1.8 years, with one annual generation; and a production of 0.466 gAFDW m-2 year-1 and a P/B ratio of 2.13 year-1. S. squamata had a production of 0.586 gAFDW m-2 year-1 and a P/B ratio of 2.78 year-1, and a mean life span of 0.57 years. M. quinquiesperforata showed spring recruitment, a life span of 4.4 years; and a production of 17.457 gAFDW m-2 year-1 and a P/B ratio of 0.90 year-1. C. major, with an annual cohort and life span of 3 years, showed a secondary production of 9.339 gAFDW m-2 year-1 and a P/B ratio of 1.02 year-1. The beach's macrofauna secondary production was low, in a general view, which is probably the result of low input of macrodebris and a low primary productivity of the area.