One of the main criteria of religious conversion is personal change. While there is broad agreement on the notion of change as the defining characeristic of conversio, there is less consensus about precisely what the change entails, and also what the key factors are in the process of change. The same thing applies to explaining the process of conversion. Different sociological theories offer divergent accounts of the conversion process. The objective of the present study is to explore the kinds iof personal change which occur in the context of conversion to Zen, by firstly defining conversion to Zen, adn secondly, offering a theory of conversion to Zen. Three forms of data were used in the research: a) interview data collected from semi-structured interviews with 34 Zen practitioners; b) field notes taken during a long period of participant observation and participation; c) notes from Zen literature and journals published by a number of Zen groups. The study firstly found the character and content of changes which the informants attributed to Zen practice and arrived at a definition of conversion to Zen which is consistent with the experience of the informans. Specifically, it was found that these changes fit in with those definitions of conversion which place drastic changes in beliefs and the identity of the converts at the core of the process. The second finding of the study was that, given the experience of my informants a successful account of the process of coversion to Zen should incorporate both the socio-cultural as well as the social-psychological levels of analysis. At the socio-cultural level, conversion to Zen is related to the culture of postmodernity. The socio-psychological level of analysis focuses on two key factors in the dynamics of conversion. The role of Zen community as a reservoir of meaning and a rederene point for a new identity, and the role of the actively regotiating individual. Conversion emerges out of the dialectic between the religious community and the individual. The results of this study suggest that conversion to Zen involves fundamental changes in the converts and these changes result from a dynamic process involving the interaction of individuals with the broader social, cultural and organisational context. I have conceptualised this interaction in terms of the process of socialization. Furthermore, I have demonstrated that socialization into the belief system of Zen Buddhism is best understood by taking an approach based on social-psychology and socio-linguistics. This approach takes into account the normative as well as the evaluative role of the religious group in the conversion process. Among other things this approach suggests that the deterministic theories of conversion, which focus on the subjective and predisposing factors, are inadequate in accounting for conversion to Zen. Furthermore itaddresses shortcomings of models of conversion to Zen which describe it as de-socialisation.