Brief Acceptance and Commitment Therapy (ACT) interventions are well-suited to facilitate timely access to effective treatment for patients experiencing common mental health concerns. This study piloted a 4-session virtual ACT group for primary care patients experiencing symptoms of depression and anxiety (n = 21). Changes in symptoms of depression and anxiety, psychological flexibility, and quality of life (QoL) were examined at post-treatment and at 1- and 3-month follow-up. At a group level, there were significant reductions in symptoms of depression for all time points and symptoms of anxiety were significantly reduced at 1- and 3-month follow-up. Measures of psychological flexibility and QoL were significantly improved at 1- and 3-month follow-up. Reliable change index scores revealed high proportions of individual improvement for depression and anxiety symptoms (56–83% across time points). Proportions of reliable change ranged from 25 to 50% for measures of psychological flexibility and QoL at 1- and 3-month follow-up. Overall, these results are comparable with previously reported rates of improvement for empirically supported treatments and provide preliminary evidence for the effectiveness of this brief ACT intervention delivered in a community setting.