Research on professional development (PD) in higher education settings is still scarce and little is known about how contextual factors influence PD of English as a foreign language (EFL) lecturers. Employing a transcendental phenomenological approach, this study seeks to extend research on this topic in order to understand how PD currently functions and could potentially function within the tertiary education reforms system in Vietnam. Drawing on ecological systems theory, this study demonstrates that the global, national, institutional and individual contexts had both negative and positive impacts on the EFL lecturers' PD experiences. The findings from this study highlight that PD of Vietnamese tertiary EFL lecturers is driven by imposed policies in response to the national education reforms and mainly top-down, but the actual engagement is grounded in lecturers' individual motivation and responsibility. This study has enabled a fuller explanation of Vietnamese tertiary EFL lecturers' lived experiences of PD from a new, more systemic, perspective. This study has addressed a gap in this area in the field of ELT in Vietnam and may be applied to other international contexts.