With the proliferation of smartphones such as the iPhone, mobile phones are being used in novel ways to promote smoking cessation. This study set out to examine the content of the 47 iPhone applications (apps) for smoking cessation that were distributed through the online iTunes store, as of June 24, 2009. Each app was independently coded by two reviewers for its (1) approach to smoking cessation and (2) adherence to the U.S. Public Health Service's 2008 Clinical Practice Guidelines for Treating Tobacco Use and Dependence. Each app was also coded for its (3) frequency of downloads. Apps identified for smoking cessation were found to have low levels of adherence to key guidelines in the index. Few, if any, apps recommended or linked the user to proven treatments such as pharmacotherapy, counseling, and/or a quitline. iPhone apps for smoking cessation rarely adhere to established guidelines for smoking cessation. It is recommended that current apps be revised and future apps be developed around evidence-based practices for smoking cessation. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.