Whether Willingness to Communicate (WTC) is a permanent trait or is modified by situational context has previously been investigated in various studies (e.g. Cao & Philp, 2006; Kang, 2005; MacIntyre & Legatto, 2011). However, most research into WTC has been quantitative or conducted in the English as a Foreign Language (EFL) or Study Abroad situation in countries such as Canada, Japan, Korea and China. This article reports on the qualitative component of an exploratory mixed methods study in a New Zealand (NZ) university with participants who are permanent migrants from Iran. These students completed a questionnaire and participated in further in-depth semi-structured interviews. The article provides an overview of previous research into WTC and motivation in Iran and NZ as the context for these three case studies. In this study, six factors, both trait and situational, were identified as having an effect on these students' WTC in both countries: self-perceived competence; personality; anxiety; motivation and the importance of English; and the learning context. Finally, this article discusses the contribution of this study to the WTC field of research, identifying the implications of these results for teachers of English in the ESL (English as a Second Language or migrant) context and possible avenues for future research.