To explore the clinical features of idiopathic hypertrophic pachymeningitis (IHP). Methods: Total 5 patients with IHP were enrolled. Their clinical profiles, laboratory examination, MRI features, and treatment were retrospectively analyzed. Results: All 5 patients were male. The median age was 57. All patients experienced headache as initial symptom. Cerebrospinal fluid protein level was elevated in all patients, and blood sedimentation was abnormal in 4 patients. C-reactive protein level was elevated in 1 patient. ANA results were abnormal in all patients. All patients showed diffuse or focal dura mater enhancement on MRI. Diagnosis of IHP was confirmed with biopsy in 2 patients. All received large dose hormones followed by small doses of hormones, and after extended treatment, headache was relieved in all patients. Patients were followed-up for 1 year during which contact was lost with 1 patient and the remaining 4 patients showed no recurrence of headache. Conclusion: IHP is clinically rare. Headache is the most common symptom, and it may also present with cranial neuropathy or other neurological deficits. Blood sedimentation and C-reactive protein in patients may be elevated, and rheumatoid immune series ANA results are usually abnormal. Abnormal signals on MRI provide important clues for diagnosis, and pathological biopsy is the gold standard for confirming diagnosis. Most patients show good prognosis, but there is a risk of recurrence.