This paper addresses orientation and mobility (O&M) training for people with multiple severe disabilities including visual impairments. The historical origins of O&M training are reviewed, noting difficulties with applying the traditional curriculum with such groups as very young children, the elderly, and those with multiple disabilities. A philosophical and theoretical perspective on O&M for those with multiple disabilities notes the importance of instruction within natural environments. Several models for serving this population are described, based on such principles as instruction within natural settings, functionality of skills, use of operant training procedures, and collaboration by a transdisciplinary team. Some adaptations of technique and equipment are discussed. (Contains 10 references.) (DB)