Supervisory feedback on theses is central in the socialisation of students into the literacy and philosophical customs and ideals of their disciplines. However, available literature suggests that while abundant anecdotal and perceptual evidence exists about the nature of written supervisory feedback and the rationale for its provision, information on the actual kinds of written feedback university supervisors provide and how the comments scaffold students' progression on their writing is inadequate. This study therefore examined the written feedback provided by thesis supervisors at the postgraduate level in a Ghanaian university. Adopting the Sociocultural Theory within a qualitative content analysis method, comments provided on fifty-five (55) chapters of master's students' thesis drafts conveniently sampled from three (3) faculties of a public university were analysed for their focus. The results reveal that the supervisors' feedback focus on content knowledge, genre knowledge, cohesion, and linguistic accuracy and appropriateness. The findings imply that supervisors need to develop the adequate knowledge of the subject matter and employ appropriate tone and style in the provision of feedback in order to provide appropriate support for the transitioning of their supervisees from novice to experienced writers within academic discourse communities.