Cancer survivors engaged in either six-week Internet-delivered mindfulness training or a usual-care control and were compared on the following outcome battery: The Hospital Anxiety and Depression Scale, the Profile of Mood States, the Pittsburgh Sleep Quality Index, and the Fatigue Symptom Inventory. Assessments were conducted before and after treatment and intervention compliance was monitored. Mindfulness treatments were delivered at a time and on a computer of the participants’ choosing. Multivariate analysis indicated that mindfulness training produced significant benefits on all measures (p < .05). Online mindfulness instruction represents a widely-accessible, cost-effective intervention for reducing psychological distress and its behavioral manifestations in cancer survivors, especially those who are unable to participate in in-person training.