Kitui County in Kenya’s Lake Victoria Basin is characterized by a rapidly growing population, water scarcity, falling food production and low resilience to climate change. The combined effects of climate change and rapid population growth are increasing food insecurity, environmental degradation, and poverty levels in the county. The county’s environmental action plan identifies population dynamics, environmental degradation and climate change as key development challenges. These issues need to be linked in county policies and programs to ensure that projects that address them are implemented jointly. Addressing population growth, environmental degradation, and climate change together should be a top priority if Kitui County is to achieve sustainable development. The county government, donors and program implementers should develop policies and implement programs that integrate population dynamics, environment/climate change, and development.