One important task in the decision making process in an organization is that of brainstorming. In a Group Support System (GSS) environment, electronic brainstorming is enabled by special hardware and software that introduces both task gains and losses; and process gains and losses. The impacts of time pressure on task completion and task quality are important concerns for managers. Specifically, we focus on the impacts of time pressure on electronic brainstorming in terms of idea quantity per unit time (idea generation rate) and idea quality (creativity). One hundred and two undergraduate business students were subjects in an experiment examining the impacts of time pressure on: (a) the rate of ideas generated; and (b) the quality (creativity) of the generated ideas. In the treatments, we varied the amount of time available for working on an electronic brainstorming task over time. Social Entrainment Theory indicates that there will be a lasting effect as the length of time to perform a task over several treatments is varied. We hypothesize that the impacts explained by Social Entrainment Theory will occur in the GSS setting. Our results support the research hypotheses that the mean rate of: (a) idea generation, and (b) the creativity of the ideas is unequal in groups operating under different time pressure conditions.