A randomised single-blind controlled trial was designed to determine whether intensity of therapy (physiotherapy and occupational therapy) shortened length of stay for patients in a rehabilitation unit. Patients were under 65, primarily with stroke, but also with other conditions such as traumatic brain injury, and multiple sclerosis. The experimental group were timetabled to receive 67% more therapy in any given week, than the control group. After controlling for confounders and case mix (as expressed by type of therapy required) patients in the experimental group showed a significant 14-day reduction in length of stay (<0.01). Concurrently average length of stay was increased for both groups by 16 days due to delays in discharge.