Background Mig‐SCog is a 9‐item questionnaire developed to quantify attack‐related cognitive complaints in migraine (M). The items relate to executive function and language, and the total Mig‐SCog score is the sum of those scales. Objective To evaluate the Mig‐SCog scores regarding cognitive symptoms during a variety of conditions. Methods We conducted a prospective comparative study of the Mig‐SCog scores (1) between migraine and tension‐type headache (TTH) patients during a headache; (2) in migraine patients between migraine attacks, non‐headache pain and pain‐free status; (3) in migraine patients during and outside a migraine attack. Results One hundred forty‐nine patients (98 M and 51 TTHA). Total Mig‐SCog score was higher in migraine patients than TTH (8.0 ± 4.1 vs 3.4 ± 3.2, P < .0001). Sixty‐three patients took part in the next part of the study. Migraine patients rated the Mig‐SCog higher for migraine (7.9 ± 4.6) than for non‐headache pain (2.3 ± 2.9, P < .0006) or pain‐free (1.6 ± 2.4, P < .0006). In the final phase of the study, 38 patients Mig‐SCog scores were not significantly different whether obtained during or outside an M attack ( P = .26). Conclusions Attack‐related subjective cognitive symptoms, assessed by Mig‐SCog scores, differed between migraine and TTH patients. The Mig‐SCog scores from migraine patients were found to be higher during migraine than during non‐headache pain or pain‐free conditions. Patient scoring from memory for usual attacks was not significantly different to scoring within attacks, We believe this demonstrates negligible recall bias.