Objectives: The present open-label multicenter pilot study sought to prospectively evaluate the efficacy and safety of rimegepant in treating migraine attacks. Methods: The primary endpoint was pain freedom at two hours post-dose, while the co-primary efficacy endpoints included a reduction in the headache intensity and freedom from the most bothersome symptoms (MBS) associated with migraine at the same time point. To test the potential efficacy of rimegepant, patients were asked to record in a questionnaire all the relevant changes with each migraine attack treated with rimegepant at two hours post-dose vs. two hours before. The attending neurologists provided information on the basic demographics, medical anamnesis, and migraine history as well as the triptan use history. Results: A total of 54 patients (32 with episodic and 22 with chronic migraine) received rimegepant 75 mg at least once during a single migraine attack (overall, 140 dosage intakes). Pain freedom at 2 h was achieved in 45/140 (32.1%) intakes. Regarding the efficacy of the first rimegepant dose (n = 54), significant reductions in the headache intensity were observed between the pre- and 2 h post-treatment average VAS scores (−4.8 ± 2.8 mean; p < 0.001). Likewise, the same mean reductions in the average VAS scores occurred when the 2 h response to all 140 doses was analyzed (−5 ± 2.8; p < 0.001). Freedom from MBS at 2 h post-dose was achieved for photophobia in 43%, for phonophobia in 53%, and for nausea in 57%. The ability to fully return to everyday activities at 2 h post-dose was achieved in 83/140 instances (59%). We only recorded mild adverse events in 24/140 dosages. Conclusions: Our preliminary results demonstrate that rimegepant is effective, safe, and well tolerated in treating acute migraine attacks.