Within Primary Care, clients presenting with mental health problems are most likely to report the presence of an anxiety disorder. Referrals to mental health services can result in waiting lists due to the prevalence of individual models of intervention. A service delivery innovation to this organizational impasse has been White's group-based “Stresspac” approach. The current project attempted to increase the effectiveness of such service delivery via the application of practice-based evidence (PBE) guidelines. Clients completed a battery of psychometric tests prior to engaging in and on completion of a six-session group cognitive-behavioural intervention. A satisfaction survey was completed on termination of the group. Two groups were completed, the second of which was conducted using a PBE derived selection criterion. The application of the PBE selection criterion appeared to increase the effectiveness of the intervention provided, with clients in both groups being widely satisfied with the group approach. The active employment of PBE in the design and implementation of services appears to offer the opportunity for increasing the range, format and effectiveness of psychological interventions offered.