Findings from recent research reveal that the ductility, toughness and resistance to tensile cracking of clays can be improved with the inclusion of short fibers. Tire buffings derived from the tire retread process can be elongated in shape and may be utilised as fiber reinforcement elements. The objective of the present research is to study the compaction and shear strength behavior of clay with tire buffing inclusions. Mixtures of low-plasticity kaolinitic clay with 10% by dry weight of tire buffing inclusions were prepared at both standard and modified compaction energy. The drained and undrained responses of the clay and composite soils were evaluated using the direct shear test. It was found that the drained shear strength of the clay was essentially unchanged by the introduction of rubber buffings or by an increase in the level of compaction energy employed. Its undrained strength was also not changed when standard compaction energy was used, but decreased slightly, showing a more ductile failure, when modified energy was employed. Good compaction of the mixture is not possible when the water content is much drier than the plastic limit of the clay. © 2006 Thomas Telford Ltd.