Since the 1950s, the relationship between the Chinese in Thailand and their host society was characterized as that of assimilation. The main proponent of this view was William Skinner, and it was subsequently adopted by researchers in the field. However, the thesis of assimilation has been challenged by writers such as Chan Kwok Bun and Tong Chee Kiong, and many would agree that Skinner's thesis no longer prevails. While it is now almost certain that the presumption of assimilation is misguided, language shift has nonetheless taken place. In the present article, the author evaluates the analysis of the factors which an earlier work claims to have contributed to assimilation and language shift (namely the decline of Chinese education, pro-Thai policies, and positive attitudes towards Thai society). In addition, she presents the arguments which have been used to discredit the thesis of assimilation. Finally, taking into account the views of other writers on the subject, she analyzes data from her fieldwork and shows that language shift has occurred.