CHEST would like to thank the individuals listed below who served as reviewers for CHEST in 2009. Without their generous assistance, the Journal would not be able to function. The expert evaluations of manuscripts by these people is a primary reason that CHEST is one of the most respected journals in its field. We extend our appreciation. Because of production constraints, we have only listed those who completed reviews by mid-October 2009. Those who completed reviews after then will be listed next year.