Ventriculus terminalis is a space which is coated by ependymal cells in conus medullaris of medulla spinalis. It is formed during the embryonic development, also known as the ependymal cyst or the 5th ventricle. This rare entity in adults can be detected on thoracolumbar MR images. It is useful to know the intensity of the image in distinguishing it from the cystic tumors located in the same region. Two middle-aged female patients referred with low back pain complaint and thoracolumbar region images obtained by routine magnetic resonance imaging sequences. The MR images revealed the cystic dilatation of ventriculus terminalis with a well-defined outline, with no septation, cord edema and additional spinal abnormality.