Zambia has experienced rapid urban growth, primarily characterized by informal development. This study identifies the dual land tenure system, comprising customary and leasehold tenure, as the principal factor hindering the sustainable growth and development of Lundazi town. The research focuses on establishing how this dual land tenure system impacts Lundazi and other regional capitals facing similar challenges. Qualitative methods were employed for data collection and analysis, including interviews with developers in both state and customary areas and structured interviews with key informants. Qualitative data were analyzed using content analysis, while the geographical information system (GIS) was used to produce maps illustrating the findings. Findings reveal that the dual land tenure system has both negative and positive consequences on Lundazi’s growth and development, with the negatives outweighing the positives. The fact that the town is surrounded by customary land impedes smooth expansion, limiting the capacity of spatial planning authorities and resulting in haphazard development and proliferation of informal settlements. Addressing these challenges requires integrated development planning (IDP), enabling collective planning encompassing both leasehold and customary tenure. Additionally, a comprehensive land administration framework is recommended to harmonize the dual land tenure system and integrate them into spatial planning, aligning with the objectives of the Sustainable Development Goal (SDG) 11.