ObjectiveThis study aimed to investigate calcitonin gene-related peptide (CGRP) levels in children and adolescents with primary headache.MethodsAll patients underwent blood sampling regardless of their headache state (ictal or interictal) on the day of examination. The patients were grouped based on their headache diagnosis (migraine, tension-type headache, or mixed).ResultsNinety-two patients aged 5-18 years were included (29 diagnosed with migraine and 31 with tension-type headache). In the comparisons between the patients with migraine and the patients with tension-type headache, interictal CGRP levels in blood from the cubital vein showed no significant difference. Ictal samples were collected in the tension-type headache group only, and no significant difference was observed between the ictal and interictal phases. Variables such as headache diagnosis, sex, age, family history with primary headache, headache frequency, time since last headache, medication usage, and body mass index did not significantly influence CGRP levels.ConclusionNo significant difference in interictal CGRP levels between patients with migraine and patients with tension-type headache were found. In patients with tension-type headache, there were no significant differences between CGRP levels in the ictal and interictal state. We were not able to draw conclusions about differences in ictal levels of CGRP in patients with migraine compared with patients with tension-type headache, or in differences between ictal and interictal levels in patients with migraine. Future studies should aim to replicate these results in a larger study cohort.