The main goals of this study were to determine the prevalence, frequency and severity of challenging behaviour in people with profound intellectual and multiple disabilities (PIMD). Because in the literature several health problems and sensory impairments are associated with the onset and existence of challenging behaviour, this relationship was also examined. This study involved 181 people with PIMD (age: mean: 35; SD: 19, 56% male). The Behaviour Problem Inventory was used to determine prevalence, frequency and severity of self-injurious (SIB), stereotypical and aggressive/destructive behaviour, and an additional questionnaire was used to determine the presence of sensory impairments and health problems among the participants. Results show a prevalence of 82% for SIB and stereotypical behaviour in the sample. Aggressive/destructive behaviour was seen in 45% of the participants. Concerning the frequency, on average SIB occurs on a daily or weekly basis. Stereotypical behaviour is seen on a daily basis and aggressive/destructive behaviour is usually reported once a week. All three types of challenging behaviour also occur on an hourly basis. The severity of challenging behaviour is usually rated by staff as of minor consequence for the person with PIMD. Furthermore, a relationship was found between having visual, tactile or psychiatric problems and the occurrence of challenging behaviour. Participants with visual impairments, tactile impairments or psychiatric problems showed significantly higher mean scores regarding challenging behaviour. Challenging behaviour within the target group of people with PIMD is very common. The prevalence figures are high, but direct support professionals are not inclined to rate such behaviour as of serious consequence. (Contains 5 tables.)