INTRODUCTION: Cognitive symptoms are reported commonly throughout all phases of a migraine; however, there is a paucity of objective cognitive profiling. Previous studies have been limited by practice effect, and variable populations. METHODS: Participants completed 1 month of daily testing with a computerised cognitive battery involving a simple reaction (SRT), choice reaction (CRT) and a working memory test (WM). Results were correlated with their diary to identify interictal scores, and scores during each phase of a migraine, and non-migraine headache days. RESULTS: A total of 16 patients with episodic migraine participated. During the headache phase of a migraine, responses to SRT, CRT and WM tasks were significantly slower and less accurate than interictally. During the postdrome, WM task performance was slower and less accurate. Non-migraine headache days were not associated with significant change. CONCLUSION: The headache and postdromal phase of a migraine day was associated with objective evidence of cognitive dysfunction in patients with episodic migraine.