Teaching evaluations are an important measurement tool used by business schools in gauging the level of student satisfaction with the educational services delivered by faculty. The growing use of online teaching evaluations has enabled educational administrators to expand the time period during which student evaluation of teaching (SET) surveys can be completed by students. This added benefit increases the complexity of data collection and introduces new questions related to the time window during which SET survey administration should commence and stop. This article examines the role of the timing of SET survey completion on student satisfaction measures in the context of online marketing courses. The results indicate that there are significant differences between those students who respond early to survey invitations and those who respond late. Early responders and late responders reflect different segments of the student body, have different course evaluation formation dynamics, and exhibit different grade expectations. The findings suggest the existence of systematic biases in SET scores related to response rate, requiring educators to closely examine policies related to the timing of SET survey administration.