School-based occupational therapy is the largest employer of occupational therapists. School-based occupational therapists work extensively with students with severe disabilities. Over the past decade, one significant change in the field of severe disabilities has been the advocacy of best practices. This paper discusses the implications of best practices for school-based occupational therapy practice and examines strategies that occupational therapists use to tackle such challenges. Focuses of the discussions are centered on the issues relative to curriculum, educational setting and instructional strategies. The theme of "Activity and Participation" proposed in "International Classification of Functioning" (WHO, 2001) guides our discussions. Specific strategies in aligning school-based occupational therapy practice with best practices in severe disabilities are proposed and highlighted. (Contains 2 tables.)