At present there is little evidence documenting children's possession-based behaviours during play within preschool settings. This ethnographic study observed the same group of 12 children over a four-month period during sustained bouts of indoor and outdoor play. An event sampling approach was employed in order to identify episodes of possession-based disputes and ways through which children with or without the involvement of the adult negotiate and resolve them. The results captured (1) the total amount of possession-based disputes, episodes where practitioners (2) were involved in the play during disputes, (3) were successful in supporting children's resolution of possession-based disputes, and finally, (4) disputes resolved through the first-possession heuristic. The findings show how children experience possession-based disputes in relation to the contextual factors of the environment and the role of the practitioner; underlying the broader socio-cultural implications of learning culturally relevant social skills and knowledge.