This study reports the findings of a randomized controlled trial (RCT) investigating the feasibility, tolerability, acceptability and initial estimates of efficacy of mindfulness-based cognitive therapy (MBCT) compared to a delayed treatment (DT) control for chronic headache pain. It was hypothesized that MBCT would be a viable treatment approach and that compared to DT, would elicit significant improvement in primary headache pain-related outcomes and secondary cognitive-related outcomes. Mixed design ANOVAs were conducted on the sample of eligible participants who did not commence treatment (N=4), the intent-to-treat sample (ITT; N=36), and on the completer sample (N=24). Results indicated that overall, MBCT represents a feasible, tolerable and acceptable treatment option for headache pain; statistical indicators for these outcomes are reported. ITT analyses showed that compared to DT, MBCT participants reported significant improvement in pain interference, self-efficacy, and activity engagement, whereas the DT group did not. Results of the completer analyses produced a similar pattern of findings; additionally, MBCT completers reported significantly improved pain intensity and pain catastrophizing whereas DT completers did not. The clinical significance of the findings is reported. Some preliminary support was found for the proposed MBCT for pain conceptual model; however, many of the hypothesized mediational pathways were precluded from analysis. This is the first study to empirically examine a MBCT approach for the treatment of chronic headache pain. Results provide a research base for future RCTs comparing MBCT to attention control, and future comparative effectiveness studies of MBCT and cognitive-behavioral therapy.