[영문]Several studies have indicated the importance of challenging behaviour as a limiting factor on quality of life (Murphy et al., 1996; Brown and Thompson, 1997; Schwartz, 2003). This article presents the findings of research that aimed to investigate adults with learning disabilities’ understanding and experiences of what is perceived by staff and services to be challenging behaviour. This study was the final phase of research reported previously in this Journal (Hayden and Stevens, 2004). Interviews, group discussions and observations were carried out with twenty-six people with learning disabilities using social services’ residential and day services. Participants were able to articulate complex responses about challenging behaviour, which is characterized as a ‘moral web’: a complex network of antecedents, behaviours and consequences. Social care staff were seen by participants to play a key role: protecting people and ensuring that appropriate (negative) consequences were suffered by instigators of challenging behaviour. These findings are interpreted within a positioning theory perspective, suggesting the importance of understanding the ways that challenging behaviour is constructed through social interaction. Implications in the following areas are discussed: developing practice; the role of social care staff; and the study of challenging behaviour as a social phenomenon.