Rizatriptan is an effective and fast acting drug for the acute treatment of migraine. As with any other acute treatment for migraine, headache recurrence may occur in up to one-third of responders. Combination with non-steroidal anti-inflammatory drugs (NSAIDs) seems to reduce the incidence of headache recurrence in clinical practice. Rofecoxib is a member of a new class of NSAIDs, which selectively inhibits the COX-2 enzyme and therefore is associated with a lower risk of gastrointestinal side-effects; the drug has a long plasma half-life (17 h). This open label study compared rizatriptan with rizatriptan plus rofecoxib in the acute treatment of migraine. Fifty-six triptan naive patients from a tertiary centre (37 women and 19 men, ages 16-55 years, mean 35 years) with International Headache Society migraine were randomized into two groups. They were instructed to treat three consecutive moderate or severe attacks with either 10 mg rizatriptan (group 1: 18 women and 10 men) or with 10 mg rizatriptan plus 25 mg rofecoxib (group 2: 19 women and 9 men). The presence of headache and nausea at 1, 2 and 4 h, and of side-effects, use of rescue medication and recurrence were compared. Fifty-four patients completed the study. Group 1 treated 76 attacks and group 2 treated 81 attacks. Absence of headache at 1 h was seen in 19 attacks (25%) in group 1 and in 34 attacks (42%) in group 2 (P =0.082); at 2 h absence of headache was seen in 60% of group 1 attacks and in 76% of group 2 attacks (P =0.115). At 4 h, 75% of group 1 attacks and 88% of group 2 attacks were pain free (P =0.122). With regard to nausea, of those who had nausea at baseline, 31% and 49% of attacks in groups 1 and 2, respectively, were nausea free at 1 h (P =0.091), 75% and 79% at 2 h (P =0.736) and 82% and 91% (P =0.479) at 4 h. Recurrence, based on all attacks of those patients who achieved pain free at 4 h, was observed in 53% of group 1 and 20% of group 2 attacks (P <0.001). Sustained pain-free rates (for the 4-h time point) were 45.6% of group 1 and 78.9% of group 2 attacks. There were no significant differences with regard to rescue medication consumption after 4 h and side-effects in both groups. There was a non-significant trend for the combination group to have a higher response rate. The group treated with rizatriptan and rofecoxib had a lower recurrence rate than the group treated with rizatriptan. This study demonstrated that combining a fast acting triptan such as rizatriptan with rofecoxib reduced headache recurrence rates, was well tolerated and may be more effective than the use of rizatriptan alone. Double-blind, placebo-controlled studies are necessary to confirm these observations.