Multi-sensory environments are widely used with autistic children. However, there are no data on how autistic children choose to spend time in the room and how this relates to their sensory, behavioural and intellectual profiles. We observed the frequency and duration of visits to multi-sensory environment equipment of 41 autistic children during 5 min of free play. At a group level, the bubble tube and touch, sound and light board were both highly popular, with the fibre optics and tactile board receiving less attention. Sensory seeking behaviours were more commonly observed in the multi-sensory environment than sensory-defensive behaviours. We found that observed sensory seeking behaviours, along with parent-reported sensory behaviours and non-verbal intelligence quotient, were associated with specific patterns of multi-sensory environment equipment use, but broader autistic behaviours were not. These data suggest that the multi-sensory environment equipment preferences of autistic children are related to individual differences in sensory behaviour and non-verbal intelligence quotient. This information has the potential to inform the development of best-practice multi-sensory environment guidelines that focus on individual needs. Lay abstract Multi-sensory environments, often called sensory rooms, are widely used with autistic children. However, we know very little about how autistic children choose to spend their time in multi-sensory environments. We also do not know how their equipment preferences relate to their individual characteristics such as their sensory differences, level of ability or general autistic behaviours. We measured the frequency and duration of visits to multi-sensory environment equipment of 41 autistic children during 5 min of free play. The bubble tube and touch, sound and light board were both highly popular, with the fibre optics and tactile board receiving less attention. The children displayed significantly more sensory seeking behaviours in the multi-sensory environment than sensory-defensive behaviours. These sensory seeking behaviours, as well as the sensory behaviours that their parents reported they showed in daily life, were associated with specific patterns of multi-sensory environment equipment use. Non-verbal ability was also associated with multi-sensory environment equipment use, but broader autistic behaviours were not. Our findings show that the multi-sensory environment equipment preferences of autistic children are related to individual differences in sensory behaviours and non-verbal ability. This information could be useful for teachers and other practitioners who want to know how best to use multi-sensory environments with autistic children.