There is a tension between conducting comprehensive systematic reviews and completing them in time to meet policy-making deadlines. The "rapid evidence assessment" has been proposed as a solution to this; offering rigorous reviews in a condensed timescale. While used frequently in healthcare, this mode of reviewing presents considerable challenges in social policy. We describe some potential problems and suggest reviewing strategies that can overcome some of them. There are situations, however, in which it may not be feasible to embark on a rapid review, and caution should be exercised when selecting this method.