Tourism is today one of the largest and fastest growing economic sectors in the world. It has largely become popular, and even become massive within the past few years. It is now possible for the greatest number of people and for an ever lower cost to go all over the planet with always fewer obstacles. It thus entails competition between the countries to welcome the largest number of tourists. In South-East Asia, Thailand is particularly famous as a tourist destination, and attracts tourists from all over the world. Tourism is undoubtedly an important primary source of foreign exchange and employment in Thailand, and helps the country to develop its economy. Nevertheless, the tourism industry is nowadays mostly characterized by mass tourism in Thailand. Despite the economic advantages mass tourism brought, mass tourism also implies many ecological, social and cultural problems for Thailand and all over the world. Among the degradations generated by tourism industry in Thailand, there are: environmental degradation and pollution, destruction of ecosystems and biodiversity, depletion of water resources, waste, coastal erosion, animals mistreatment… and climate change. Climate change will increase the probability of important natural disasters that may cause dramatic damages to the local populations. All these factors will impact the country; influence its future and the choice of the tourists’ destinations. Therefore, it will have a direct impact on the economy if the tourists choose Vietnam, the Philippines, Cambodia and Indonesia over Thailand to travel. A possible answer to tackle these issues could be to get inspiration from Costa Rica. This little Central American country based all its tourism strategy on ecotourism, which aims to have as little impact as possible on the natural environment. It also has an important focus on the education of tourists and aims at raising awareness on the necessity of preserving biodiversity. Thailand is still able to initiate change by looking forward and choosing a long term approach concerning its tourism industry. But Thailand needs to have the courage to implement some new measures and to follow them.