Fourteen out of twenty four provinces were affected by the storm and subsequent flash floods. The typhoon left 43 people dead, 67 people severely injured, and destroyed homes and livelihoods of some 49,000 families, or about 180,000 people, the equivalent of 1.4 percent of Cambodia’s total population. More than 210 houses were completely destroyed, 804 severely damaged, and 10,500 buildings damaged, along with widespread damages to property, livelihoods, and public infrastructure.  Most of the affected districts were among the poorest in the country.About 80 percent of the Cambodia’s territory lies within the Mekong River and Tonle Sap Basin, known to have large fluctuations of water levels between the dry and wet seasons causing an annual cycle of droughts and floods. It is estimated that floods cause agricultural losses of USD 100–170 million each year.

In order to develop a recovery plan to ensure future disaster risk reduction (DRR), a multi-agency Post Disaster Needs Assessment (PDNA) was carried out in November 2009 with support from the Global Fund for Disaster Risk Reduction (GFDRR). The assessment team was composed of cross-agency groups, led by the National Committee for Disaster Management (NCDM) and including a wide range of line ministries and technical experts from a range of agencies, including the World Bank (WB), Asian Disaster Preparedness Center (ADPC), United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP), Asian Development Bank (ADB), World Health Organization (WHO), United Nations Development Program (UNDP), Food and Agriculture Organization (FAO), UNICEF, Save the Earth, Caritas, Oxfam GB, Plan International, and Netherlands Development Organization (SNV). 

The PDNA estimated the total damages and losses caused by Typhoon Ketsana at USD 132 million, about 1% of Cambodia’s GDP. The productive sector was the most affected (with 56% of all damages and losses), followed by the social sectors (26%), and the infrastructure sector (18%).  It was also estimated that the typhoon would lead to 0.2% point reduction in economic growth for 2009 reducing the growth rate for 2009 from earlier estimates of 2.1 to 1.9 %. The reconstruction and livelihood restoration needs in priority sectors (agriculture, transport, water management, industry and commerce, education and housing) were estimated at US$ 191 million. The medium and short-term Disaster Risk Reduction priorities were estimated at US$ 8.9 million, which includes improving the process of data collection and management; capacity building activities, improving early warning system, and mainstreaming Disaster Risk Management into policies and programs of relevant government ministries.