In South Africa, students' academic success in tertiary environments is generally low, despite governmental or institutional interventions. Underpinned by McCroskey, Valencic and Richmond's (2004) General Model of Instructional Communication, we explored lecturer and student perceptions of lecturer clarity during instruction using a mixed-methods case study. A convenience sample of seven lecturers were interviewed and observed in situ. Questionnaires were completed by 252 first year students at a large South African university. Content and statistical data analyses revealed that a mismatch existed between lecturers' perceptions of their own instructional clarity and their students'. The high percentage of students who felt lost during a lecture suggests a high level of instructional dissonance, which might account for a less-than desirable academic throughput. We recommend that institutions quality assure lecturers' oral, written, content and process clarity prior to and during appointment.