Adjustment disorder (AjD) is one of the most common disorders in clinical practice, and its symptoms are severe enough to cause great distress and functional impairment. The AjD CBT protocol specifically developed for this disorder has shown positive results when delivered face to face and through virtual reality. Despite existing evidence supporting the benefits of therapeutic homework as part of a psychological intervention, little is known about how to increase homework engagement in psychotherapy. This study examines the feasibility (doability, initial efficacy and acceptability) of a digital support system to deliver homework via the Internet in the treatment of AjD. Participants were randomly assigned to a traditional homework condition or a digital support system condition. Both interventions resulted in statistically significant improvements, with large effect sizes, in all the outcome measures at post-treatment, with no significant differences between groups. At 12-month follow-up, these therapeutic gains were maintained, and an improvement was even observed in both conditions, with no significant differences between groups. Additionally, treatment satisfaction predicted efficacy in both groups separately and when the whole group was considered. This is the first study to explore the feasibility an initial efficacy of delivering a therapeutic homework component for AjD through the Internet.