This thesis discusses how the difficult relationship between tourism and the environment, in a local context, may be improved. More specifically, it is discussed how ecotourism may be less environmentally and socio-culturally destructive. Ecotourism certification is suggested as a solution, but it is no panacea, neither is it a simple procedure. Apart from a general discussion on the subjects of sustainable tourism and environmental certification of tourism, the thesis includes a case study of the Green Palm certificate for tourism houseboats in Kerala, India. It is an example of an ecotourism certificate, and the case study highlights certain problems that similar efforts are likely to experience, and possible solutions to such problems.