Background: Concern has been expressed repeatedly about the cost and quality of residential placements for adults with learning disabilities and additional needs. This study sought to identify characteristics of the highest cost placements in the South-East of England. Method: Lead learning disability commissioners in the South-East of England were asked to provide information about the five highest cost residential placements that they commissioned for adults with learning disabilities. Results: The average placement cost of 172k British Pounds per annum disguised wide variation. Individuals placed were mainly young and male with high rates of challenging behaviour and/or autism spectrum disorder. Most placements were in out-of-area residential care. The highest costs were associated with hospital placements and placements for people presenting challenging behaviour. Conclusions: Young, male adults with learning disability, challenging behaviour and/or autism continue to receive very high cost residential support, often in out-of-area residential care. There remains limited evidence of plans to redirect resources to more local service developments. (Contains 1 table and 1 figure.)