The aim of this study is to present the effects of the application of a manualized treatment protocol in a community sample of 67 Spanish adolescents (62.68% women) in generalized social phobia (GSP), in neuroticism (N), and extraversion (E). The participants were randomly assigned to a control group (n= 33; M= 15.21 years old, SD= 1.04) and a treatment group (n= 34; M= 15.29 years old, SD= 1.10). All met the criteria required for the diagnosis of social phobia (generalized subtype, APA, 1994) and completed the Inventory of Anxiety and Social Phobia (SPAI), and the Eysenck Personality Questionnaire for children (EPQ-J) or for adults (EPQ-A) according to their age. The time looking at the conversation partner during a situational test was also quantified. The results show that: (i) the treatment is effective to eliminate / reduce GSP; and (ii) N and E show significant changes between the pretest and the posttest that are prolonged in the follow-up. The implications of these findings and the stability of N and E are discussed.