This study examined students' essay performance on topics from the Test of Written English (TWE) under time limits of 30 minutes, as currently administered, and 45 minutes. In the main groups of the study, each student wrote an essay on one topic under the current time limit and on another under the 45-minute time limit. A total of 820 intensive English and academic international students participated. The correlation between scores for the time conditions was relatively high and approached the parallel-form reliability of the task, as determined by data from students who wrote essays on different topics under the same time limits. The provision of additional time apparently had little effect on the standings of the students in relation to each other. Mean scores on the TWE were about one-fourth to one-third point higher for the 45-minute condition, indicating a modest but reliable increase in scores. The magnitude of the effect was roughly comparable for students of low and high ability. Students regarded 45 minutes as more sufficient for accomplishing the task than 30 minutes. Practical implications are discussed. Appendixes contain the topics and the scoring guide. Seven tables present study findings. (Contains 12 references.) (Author/SLD)