The objective of the article was to investigate the impact of peer review of literature search strategies in CADTH rapid reviews.  The article describes how the results of pre-peer-reviewed searches from a sample of 200 rapid reviews compared with their corresponding post-peer-reviewed search results. Those records identified uniquely by the post-peer-reviewed search, and included in the rapid review report, were analysed to see why they had been retrieved. Although peer reviewed strategies identified additional records in 75% of the searches investigated, only 4% of these records were included in the rapid review reports. The addition of more keywords and subject headings was the main contribution leading to the identification of further included studies. Different combinations of concepts also contributed to the retrieval of new studies. The article concludes that peer review of search strategies helps to retrieve additional relevant studies, and that reviews including non-randomised studies benefit most.