The treatment of chronic and recurrent depression is a priority for the development of new interventions. The maintenance of residual symptoms following acute treatment for depression is a risk factor for both chronic depression and further relapse/recurrence. This open case series provides the first data on a cognitive-behavioural treatment for residual depression that explicitly targets depressive rumination. Rumination has been identified as a key factor in the onset and maintenance of depression, which is found to remain elevated following remission from depression. Fourteen consecutively recruited participants meeting criteria for medication--refractory residual depression [Paykel, E.S., Scott, J., Teasdale, J.D., Johnson, A.L., Garland, A., Moore, R. et al., 1999. Prevention of relapse in residual depression by cognitive therapy--a controlled trial. Archives of General Psychiatry 56, 829-835] were treated individually for up to 12 weekly 60-min sessions. Treatment specifically focused on switching patients from less helpful to more helpful styles of thinking through the use of functional analysis, experiential/imagery exercises and behavioural experiments. Treatment produced significant improvements in depressive symptoms, rumination and co-morbid disorders: 71% responded (50% reduction on Hamilton Depression Rating Scale) and 50% achieved full remission. Treating depressive rumination appears to yield generalised improvement in depression and co-morbidity. This study provides preliminary evidence that rumination-focused CBT may be an efficacious treatment for medication--refractory residual depression.