The relationship between marine benthic foraminifera assemblages and the environment has been examined from samples collected across the southern edge of Langebaan Lagoon. The assemblages show a vertical zonation that can be related primarily to altitude above mean sea level and secondarily to type and abundance of plant cover. The foraminiferal analysis distinguishes three zones: a high marsh zone dominated by a monospecific Trochammina inflata assemblage, a middle marsh zone consisting of variable abundances of T. inflata and Jadammina macrescens; and a low-marsh and tidal zone dominated by calcareous species such as Ammonia japonica, Ammonia parkinsoniana, Elphidium sp. A. Elphidium cf. articulatum and Quinqueloculina sp. The altitudinal range of these foraminiferal zones is used to reconstruct relative changes in late Pleistocene sea level from a succession exposed at Monwabisi on the False Bay coast.