Providing a deadline for sample members to respond could potentially have either a positive or negative effect on the speed with which survey responses are received and on the overall response rate. On one hand, letting sample members know that there is a short window of time for them to respond may lead them to respond quickly for fear of missing the opportunity to participate. On the other hand, providing a deadline may appeal to respondents’ tendency to procrastinate right up until the deadline, thereby slowing the speed of response. A deadline also may suppress response rates if it leads respondents who feel pressed for time to discard the survey request because of the impression that they will not have a chance to respond before the imposed deadline. It also is reasonable that deadlines may affect sample members in different ways depending on characteristics such as topic salience. However, there has been relatively little research looking at the effect of deadlines on survey response – and most of that which does exist is limited to mail surveys. This presentation will review the results of two recent experiments that varied whether survey sample members were given a deadline for responding. The first was a Web survey in which sample members were assigned to a deadline condition or no deadline condition. The second was a mixed-mode mail and Web survey in which sample members were assigned to (1) a short deadline condition, (2) a long deadline condition, or (3) a no deadline condition. We will report on the effect that the deadline had on the speed with which responses were received in these two experiments, as well as on the overall response rate. We also will discuss whether the deadline had an effect on sample composition and responses to key variables.