Data from a survey of marriage patterns in central Thailand illustrate the complexity of change in marriage patterns in a developing society-the diversity of traditional patterns, the different directions of change, and the variations in current patterns. The data were collected in 1978 and 1979 from ever-married women aged 15–44 in three settings:a central plains village, established areas in Bangkok, and a Bangkok squatter settlement. Three forms of entry into marriage were identified:ceremonial marriage with parental involvement in the choice of spouse, ceremonial marriage with self-choice of spouse, and nonceremonial marriage (elopement and living together). All three forms of marriage existed in each setting, and the dominant form differed in each. In general, a family background of higher socioeconomic status led to a greater likelihood of a marriage ceremony and greater parental involvement in spouse choice. Women with more education were also more likely to marry with ceremony, but higher education for daughters was associated with less parental involvement in spouse choice. These findings suggest that marriage patterns may remain diverse in Thailand, even as further development occurs.