Kitulgala Beli-lena, a rockshelter in gneiss in humid tropical southwestern Sri Lanka, was inhabited by Late Pleistocene-Early Holocene (31,000-7880 B.P.) hunter-gatherers who made geometric microliths and exploited rainforest resources. Micromorphological analysis of a ca. 3-m-thick succession of diamictic loams, clays, and breccia with cultural content suggests that relative contribution of episodic colluviation and roof fall, water seepage through joints and diverse human activity varied through time. Facies changes across the profile reflect mon-soon weakening ca. 20,000-16,000 cal B.P. and abrupt intensification ca. 15,700 cal B.P., on the wane of the global Last Glacial Maximum (LGM). Post-depositional modification included clay, sesquioxide, and minor phosphate translocation; termite and other arthropod bioturba-tion; and clast weathering on the rockshelter floor. Human input (tools and tool-making refuse, reworked charcoal and associated combustion by-products) is markedly higher in sediments younger than ca. 15,700 cal B.P., suggesting intensification of site use immediately after the LGM.