Spasticity is a common complication after a non-traumatic spinal cord lesion such as transverse myelitis and typically involves both lower limbs. However, we report on a case of spasticity involving an uncommon group of muscles (unilateral ankle dorsiflexors) following incomplete recovery of transverse myelitis. The impairment following this spasticity was greater than expected. It caused severe discomfort, gait impairment, difficulty wearing shoes and disabilities in performing activities of daily living. Treatment with botulinum toxin type A intramuscular injections to the muscles, namely tibialis anterior, extensor hallucis longus and extensor digitorum longus reduced the spasticity and improved the patient’s function.