We report a case of a non-infantile primary intramedullary spinal cord desmoplastic astrocytoma in an 18-year-old girl who presented with spastic paraparesis. The patient had been unable to run for 1 year. Magnetic resonance imaging of her spine showed an intramedullary solid and cystic heterogeneously enhancing lesion located at T7-T8 level. Partial excision was performed. Histology revealed a desmoplastic astrocytoma. To the best of our knowledge, there is no report on primary desmoplastic astrocytoma of the spinal cord in literature. Nor has such a symptomatic tumour manifesting at the age of 18 years been documented.