Abstract. Extreme weather events are common and increasing in intensity in the southwestern Pacific region. Health impacts from cyclones and tropical storms cause acute injuries and infectious disease outbreaks. Defining population vulnerability to extreme weather events by examining a recent flood in Honiara, Solomon Islands, can help stakeholders and policymakers adapt development to reduce future threats. The acute and subacute health impacts following the April 2014 floods were defined using data obtained from hospitals and clinics, the Ministry of Health and in-country World Health Organization office in Honiara. Geographical information system (GIS) was used to assess morbidity and mortality, and vulnerability of the health system infrastructure and households in Honiara. The April flash floods were responsible for 21 acute deaths, 33 injuries, and a diarrhea outbreak that affected 8,584 people with 10 pediatric deaths. A GIS vulnerability assessment of the location of the health system infrastructure and households relative to rivers and the coastline identified 75% of the health infrastructure and over 29% of Honiara's population as vulnerable to future hydrological events. Honiara, Solomon Islands, is a rapidly growing, highly vulnerable urban Pacific Island environment. Evaluation of the mortality and morbidity from the April 2014 floods as well as the infectious disease outbreaks that followed allows public health specialists and policy makers to understand the health system and populations vulnerability to future shocks. Understanding the negative impacts natural disaster have on people living in urban Pacific environments will help the government as well as development partners in crafting resilient adaptation development.