Doctoral student numbers are increasing worldwide. Students and supervisors are very mobile and supervisor-student relationships no longer simply represent a  ‘host’ university country supervisor and ‘overseas’ students. Characteristics of the sufficiently conceptual, critical and creative doctorate and ways of supervisory ‘nudging’ to enable students to achieve such quality are inflected by  cross-cultural supervisory relationships. There is a greater cultural mix with potential for culturally enriched co-construction of knowledge,  requiring cultural awareness, flexibility and appreciation of differences in learning approach, topics and methodologies. In this context most research on international doctoral students and culturally inflected learning at doctoral level tends to consider issues of language, learning differences, institutional provision. Research, development and practice explored here deriving from three research projects and a range of practices, focuses on cross-cultural supervision of culturally diverse doctoral students. It considers ways of enabling and recognising doctoral students’ conceptual threshold crossing, achievement of the quality doctorate, and in doing so considers issues of cultural capital and the ‘culturally inflected voice’ affecting students’ and supervisors’ choice of topic, context, research methodology and method, and co-construction of knowledge.