Sensory integration therapy (SIT) is a controversial intervention that is widely used for people with disabilities. Systematic analysis was conducted on the outcomes of 17 single case design studies on sensory integration therapy for people with, or at-risk of, a developmental or learning disability, disorder or delay. An assessment of the quality of methodology of the studies found most used weak designs and poor methodology, with a tendency for higher quality studies to produce negative results. Based on limited comparative evidence, functional analysis-based interventions for challenging behavior were more effective that SIT. Overall the studies do not provide convincing evidence for the efficacy of sensory integration therapy. Given the findings of the present review and other recent analyses it is advised that the use of SIT be limited to experimental contexts. Issues with the studies and possible improvements for future research are discussed including the need to employ designs that allow for adequate demonstration of experimental control.