This study presents the results of the first recent analysis of stone tool assemblages from Krapina (Croatia). All assemblages are Pleistocene in age and many are associated with human remains, the Krapina Neandertals. The assemblages are described typologically and technologically, and subtle chronological changes in raw material selection and technology of tool blank production are observed. These changes involve increasingly sophisticated and selective use of lithic materials. Changing artefact assemblages are considered in light of variability in the hominids from Krapina, and are interpreted as reflecting behavioral change among Neandertals rather than between Neandertal and modern human populations.