A sequence of samples of micromammalian remains from Klasies River Mouth on the south coast of South Africa provides evidence of vegetational and climatic change during the Late Pleistocene. The evidence suggests the presence of a vegetational mosaic similar to that of the present but with relatively more open vegetation at the time the central part of the sequence was being deposited. Fluctuations occurred in general climatic conditions, as indicated by the Shannon-Wiener index of diversity, but conditions appear to have remained relatively moderate throughout with no evidence of glacial or interglacial maxima. Changes in sea level are probably also reflected in changed proportions of various species of small mammal. The site has yet to be dated conclusively but the micromammalian data tend to suggest that this sequence of deposits was laid down during isotope stage 5, probably substages 5d-a. Human response to the challenge of changing conditions can be shown to lag behind those changes as recorded by micromammals. -- AATA