This paper employs extensive interviews to examine the ways in which perceptions of renting — on the part of renters, owners and other key actors in the development process — influenced the dynamics of participation around two recent urban development projects in Dar es Salaam, Tanzania. The study responds to concerns that participatory planning too frequently treats communities as homogenous and overlooks barriers to participation faced by marginalized groups, such as renters. The results show that renters were unwilling and often unable to participate due to perceptions, hled by themselves and by others, of renter transience and inconsequentiality. These perceptions led to a cycle of non-participation in which policymakers gave renters' needs little attention in plans and renters were disinclined to participate in mobilization. The results suggest that barriers to renter participation could be reduced if their concerns were proactively given more weight in urban development plans.