This research note reports an examination of presidential approval ratings during the Iran hostage crisis. Models of intervention and transfer function are estimated by way of Box-Jenkins and Box-Tiao analysis using Gallup opinion data from January 1976 to December 1979. Although it is fairly well accepted that the hostage crisis precipitated a "rally-round-the-flag" effect for President Carter, an examination of popularity dynamics reveals the unique influence of the crisis on Independents, a finding that suggests the need to revise the traditional view of the rally phenomenon.