The study aimed to evaluate tertiary institution students’ absenteeism to complex-course lectures in Nigeria using students from the Department of Mass Communication, Edo State University. The study was predicated on the Diffusion of Innovation Theory (DOIT). The objectives included ascertaining of the extent of Mass Communication students’ knowledgeability of complex-course teaching, whether students absent from complex-course teaching lecture and the challenges student face while attending complex-course teaching class, as well as to evaluate the reasons behind student Absenteeism from complex-course teaching. Survey research design was employed, while a questionnaire was utilized to elicit responses from 128 students chosen via census. Results showed that the extent of knowledge of complex-course teaching by the Mass Communication students of Edo State University is high. The implication of the above is that students are aware of, and can decipher what constitute complex-course teaching. Further, the findings indicate, amongst others, that more than half of the students (60%) do not absent themselves from the class, because of a complex-course. The implication of the above is that the majority of the students of Mass Communication of Edo State University do not absent from complex course lectures. Given the above, the study recommends that the University should take adequate steps to curb the challenges identified and the reasons behind students’ absenteeism from complex course teaching, as well as undertake a comprehensive and sustained review of attendance to lectures in order to properly understand the extent of the problem. It is further recommended that lecturers should engage in a one-on-one discussion with students, in order to identify other innate causes that propel absenteeism to complex courses.