This chapter is concerned with the study of the impacts of tourism on people in groups, and this includes both residents of tourism areas (such people are usually referred to as hosts) and tourists themselves. It is also concerned with impacts on the culture of the host population (and with any effects on the culture of the visitors themselves). The ways in which culture can be used and even packaged to promote tourism, and hence the subsequent effects this has on culture, are also topics investigated. As with economic impacts, socio-cultural impacts can be subdivided under two headings: positive impacts, including cultural revival and the acquisition of new skills; and negative impacts, such as the loss of traditional skills, damage to local culture, and more extreme effects such as prostitution, drunkenness and drug taking. There has also been growing concern recently over the prevalence of sex tourism in certain parts of the developing world and the effects this has had on specific groups, including women and children, and this issue is discussed in the chapter via a case study of South East Asia.