Academic staff at universities have become concerned about the decrease in student attendance at lectures and the implication of this on student achievement and learning. Few studies have measured actual lecture attendance in a coherent or comprehensive way. The aim of this study was to measure actual lecture attendance of students over two year levels enrolled in two separate science disciplines, biochemistry and pharmacology. The study further sought to determine the factors that influence lecture attendance. Attendance at lectures in four units of study was monitored over a 12-week semester. Attendance at lectures decreased over the semester and was lower at early morning lectures (8 a.m.; 9 a.m.). A questionnaire surveying students about their preparation for lectures, their compensation for missed lectures and the factors influencing their nonattendance was administered at the end of the semester. Students reported that the major factors influencing their attendance at lectures related to timetable issues and the quality of lecturing. If students missed lectures, the majority read the lecture notes and listened to the online recordings. The availability of online recordings of lectures was not a major influence on attendance at lectures. In three of the four units studied there was no correlation between self-reported lecture attendance and exam performance. The results of the study indicate that universities should dedicate more resources to timetabling and to supporting staff to improve the quality of their lectures. (Contains 7 tables and 4 figures.)