We describe 3 cases of surgically proved spinal intradural arachnoid cysts. Two cases were developed after antecedent tuberculous infection of the central ner-vous system and in 1 case the cause was uncertain but presumed to be an acquired condition. The location of the cysts were cervical cervicothoracic and thoracic spine level respectively. On the magnetic resonance(MR) images the lesions were presented as widening of subarachnoid space with spinal cord compression and atrophy. The cysts were slightly hyper-(case 1 and 2) or hypo-(case 3) intense to the cerebrospinal fluid on T1-weighted images and isointense with internal heterogeneous dark portion on T2-weighted images. In 2 cases which had pre-vious history of tuberculosis accompanying syringomyelias were noted. Precise localization and diagnosis were obtained with MR pre-operatively.