Idiopathic spinal epidural arachnoid cysts (SEACs) are relatively rare lesions with diverse clinical manifestations depending on the affected spinal region and nerve roots. To assess the relationship between clinical presentation and surgical outcome, we conducted a retrospective review of medical records and neuroimages from idiopathic SEAC patients. Of 15 consecutive patients with idiopathic SEACs, 14 underwent surgical treatment at the Beijing Tiantan Hospital between January 2008 and July 2013. Case histories, clinical presentations, imaging findings, operative findings, and surgical outcomes were reviewed. Of the 15 patients, 5 were children (median age, 13 years) and 10 were adults (median age, 35 years). The male-to-female ratio was 4:1. The median disease duration was 1 year in children and 4 years in adults. The most common manifestations were progressive paraparesis (73.3 %) and radiculopathy (66.7 %). All pediatric lesions affected thoracic segments, while 80 % of adult lesions affected lumbar segments. Fourteen patients underwent microsurgical treatment, with cyst excision in nine (combined with fistula closure in four) and partial cyst excision in five (with fistula closure in three). No recurrences were observed during follow-up (average of 23 months). Excellent outcome was achieved in six cases, good outcome in four, fair in two, and poor in two. Idiopathic SEAC mainly affect the thoracic segments in children and the lumbar segments in adults, and often results in progressive paraparesis and radiculopathy. Early surgical intervention is suggested for progressive symptomatic patients to restore neurological function.