There has been an increased use of modern information and communication technology in healthcare services in recent years; however, little is yet known about the nature of the therapeutic alliance in internet-based interventions. This review aims to give a systematic overview of controlled evaluation studies with a focus on the nature and impact of the therapeutic alliance in internet-based interventions available to date. The results of internet-based randomized controlled trials indicate that a positive therapeutic alliance can be established regardless of the medium of communication. The therapeutic alliance was rated equally satisfying as in conventional face-to-face therapy.