Social phobia is a common and disabling anxiety disorder. The most effective psychological treatments for social phobia are cognitive therapy and exposure. However, the degree of improvement across these treatments is variable, and their implementation is costly and time-consuming. This study aimed to conduct a preliminary clinical evaluation of the effectiveness of a brief, new form of cognitive therapy based on a recent cognitive model of social phobia. Six consecutively referred patients with social phobia were treated using established single case series methodology. Brief cognitive therapy was effective with all patients demonstrating clinically significant improvements in all measures. Treatment gains were maintained at follow-up. The mean number of treatment sessions delivered was 5.5 and improvements compare favourably with previous treatment studies. Brief cognitive therapy for social phobia appears promising and it is potentially cost-effective. Future randomised and controlled evaluations of this brief treatment are warranted.