The natural disaster known as "the Tsunami" occurred in Andaman coast of Thailand in December 2004, and there had been questions whether it could cause PTSD amongst the population who lives in the affected area and how to avoid PTSD condition to occur.The purpose of this study is to establish statistical results of psychosocial factors, and their correlation to PTSD and other mental disorders in order to generate the PTSD database. Cross sectional community surveys had been conducted in two phases from the same sampling group, the first phase is concerned with prevalence of PTSD, depression and related factors. Results were collected from 3,133 samples and shows that 33.6% suffered from PTSD, 14.27% with depression and 11.27% suffered from both. The second phase is focused on chronic PTSD and other mental disorders 2,573 samples were collected and only 21.6% were diagnosed with chronic PTSD.The statistical analysis has identified risks factors that could cause PTSD, and protective actions which could help to prevent PTSD.