The aim of this service evaluation was to assess the effectiveness of a cognitive behaviour therapy (CBT) group in primary care for women with postnatal depression and anxiety. Previous research has found that postnatal depression may be connected to the sometimes challenging and overwhelming transition to motherhood, and it is a condition that often goes untreated. Further research also indicates that CBT is more effective than placebo controls and antidepressants, and is gathering a robust evidence base as a treatment for this condition. This paper presents findings that looked at self-reported symptoms in women who received a CBT-based group intervention. Results show that participants did experience a clinically significant reduction in symptoms of depression and anxiety according to the Improving Access to Psychological Therapies (IAPT) reliable improvement index. This lends support to previous research and demonstrates that group-based CBT in a primary care psychology service can be effective for women with postnatal depression and anxiety.