Headache is very common symptom that nearly every person suffer from it at a point during their life. It could be either primary or secondary. "Warning flags", if associated with headache, will increase possibility of underlying intracranial abnormal process & point to the need for supplemental investigation. CT head scan is very useful tool in this regard. A cross sectional study involved 50 patients, their ages were 14 years & above, who sent for CT head scan in Al-Yarmouk teaching hospital in Baghdad over the period extending from 3 \ 3 \ 2020 to 23 \ 9 \ 2020 to evaluate their headaches that associated with worrisome flag(s). To study the role of CT head scan in patient with worrisome headache. 34% of sample associated with positive CT head scan findings, all of them were related to the etiology of headaches. All cases that showed positive CT head scan findings were patients with secondary headaches. The "neurological signs or symptoms" was the worrisome flag which associated with highest frequency (76.47%) among the cases that showed positive CT head scan findings. The study shows that every patient with secondary headaches or headaches with worrisome flags must be evaluated by brain imaging investigatory tool, & CT head scan in this regard is important yielding tool for cases with secondary headaches but not for primary headaches. The study, also, shows that "neurological signs or symptoms" is the most frequent worrisome flag in those cases which have positive CT head scan. We recommend a thorough clinical interview & physical examination in such cases.