Responding to calls for more knowledge about the motivations (and changing motivations) of self-initiated expatriates (SIEs), this qualitative research examines 58 Australian SIEs working in culturally (dis)similar host contexts, to address the question: Why are Australian SIEs motivated to expatriate to South Korea or the United Kingdom? The findings demonstrate that, although personal/lifestyle considerations are important to SIEs, career-related considerations are either primary or become more prevalent following expatriation. The findings reveal that, while SIEs expatriate with particular motivations, over time their motivations may change as other factors determine desire to stay/leave a host country. Drawing on self-determination theory (SDT), the research highlights variations in extrinsic and intrinsic motivations of SIEs including those who intended to utilise their expatriation as part of a boundaryless career and those who unintentionally found themselves focused on career. Knowledge of (changing) motivations is salient to organisations' selection decisions and support for international employees.