This study tracked the development of Hong Kong's assessment practices for English pronunciation over the past four decades, with reference to the nativeness and intelligibility principles in L2 pronunciation research and pedagogy. Specifically, it evaluated changes in assessors' comments on candidates' English pronunciation performance in school-exit public examinations between 1978 and 2018. Qualitative and quantitative content analyses were conducted on the examination report for each year to identify themes related to candidates' pronunciation 'problems', including 'word-based' features (word pronunciation, word stress, segmentals), 'discourse-based' features (suprasegmentals) and 'delivery' (clarity, fluency, loudness, naturalness, pacing). In the examination reports, candidates' problems with word-based features (particularly word pronunciation) received the most attention across the decades. Most of the comments in later reports were aligned with the intelligibility principle, particularly at the segmental level (e.g., missing consonants, simplification of consonant clusters, word pronunciation). These assessment practices were potentially influenced by the teaching methods recommended in the different ELT curricula over time (i.e., from an oral-structural to a communicative/task-based language teaching approach), and also by the assessors' judgements. The paper concludes by proposing a research agenda for the promotion of an evidence-based approach that can inform future assessment practices.