Despite growing recognition of solutions to water scarcity challenges, decision-makers across the world continue to face barriers to effective implementation of water planning, governance and management. This is evident in the cases of Lahore and Karachi in the Indus Basin in Pakistan and illustrated through the experiences of the provincial government departments and utilities. Water scarcity and associated challenges are continuing to impose significant costs on these cities, which continue to grow as water availability further declines, demand increases, water quality deteriorates, and infrastructure degrades. A team of Australian water experts was commissioned by the Australian Water Partnership to diagnose urban water challenges and identify priority actions for improved water security, in collaboration with Pakistani partners. This paper presents the outcomes of that work. This includes a synthesis of the published literature and data on the geographical, climatic, and water scarcity contexts of both Karachi and Lahore. It then identifies responses to water insecurity that have been considered or implemented in the past and the barriers that have inhibited the effectiveness of these efforts. Finally, it presents actions within five priority action areas that Pakistani stakeholders have identified as being most practical and impactful for improving water security outcomes.