Annual and seasonal changes thought to be related to variability in the direction and magnitude of longshore sediment transport are reported for the long sandy coastline of Rio Grande do Sul, southern Brazil. Recent modeling studies have indicated strongly that this variability is closely related to the wave height and direction relative to the coastline and that future changes in wave climate linked with global warming may impact significantly at the coastline. Very few measurements of wave conditions and longshore sediment transport are available for the Brazilian coastline. Thus, it is considered that further investigation of these effects are required in order to devise more effective management strategies and to plan and advise for future changes in coastal morphology.