Background: There is a need for a more accurate characterisation of higher level restricted and repetitive behaviour (RRB) in autism spectrum disorder (ASD), including why it might be considered problematic and events associated with its occurrence. Method: We selected one form of higher level RRB--arranging and ordering--that was rated as severe for a large percentage of the population sampled. We interviewed 20 students' teachers and conducted naturalistic observations for 15 of those students. Results: The characteristics of arranging and ordering varied across, and sometimes within, individuals. Problems associated with compulsive-like1 behaviour also varied, with several unanticipated reported problems. With the exception of attention, social consequences were relatively infrequent. Conclusions: These data highlight the need for research on the assessment and treatment of arranging and ordering and clinical attention to compulsive-like behaviour in ASD. Interviews and naturalistic observations are useful for structuring additional observations and analyses.