This paper discusses and reviews several of the more common causes of water infiltration into basements such as: failure of the waterproofing system, structural failure of the foundation or slab, and an increase in hydrostatic pressure. Recommendations are offered for alleviating water pressure by modifying above grade building components, altering topographical elements and the use of internal and external drains. Techniques are described for stopping water infiltration by applying negative side water-proofing materials, injecting grouts and chemicals in the soil around the foundation walls, under slabs, behind walls, and into leaking cracks and joints. The paper concludes with a review of the various materials and systems that are used for repairing leaking basements together with their pros and cons.