Private rental markets accommodate a significant share of Africa’s rapidly growing urban populations. The vast majority of tenants are accommodated in rental housing supplied by private landlords. Few studies offer insights on the dynamics and logics shaping the supply and production of private rental housing in the context of African cities. This paper contributes to fill this remarkable knowledge gap with a study of the supply and production of private rental housing by self-builder households in Dar es Salaam and Mwanza, two of the largest and fastest growing cities in Tanzania. This paper examines the motivations and aspirations of self-builder landlords, the type and quality of rental housing they supply and the logics shaping their investments in housing quality and tenants’ access to services. The paper argues that housing policies should acknowledge the significance of private rental housing in accommodating growing urban populations and the contribution of small landlords, such as the self-builders in Dar es Salaam and Mwanza, in the supply and production of private rental housing. Furthermore, any policies seeking to increase the availability and quality of affordable rental housing should be informed by in-depth understanding of the perspectives of such landlords. While concerns regarding lack of protection of tenants’ rights and sub-standard accommodation are often justified, great care is needed, as policies promoting tenants’ rights or enforcing minimum standards could undermine the supply of new rental housing or make rents wholly unaffordable for the poorest tenants.