Spinal anesthesia is commonly used for various surgeries below the umbilicus including urological surgeries.Whereas many complications occur following administration of spinal anaesthesia such as hypotension, bradycardia, high spinal, post dural puncture headache, involuntary movement of the limbs is an extremely rare complication. It presents as a sudden shock-like involuntary muscle contractions affecting a single muscle or multiple muscle groups, which often resolves untreated. The characteristic of the presentation is different from those of typical myoclonus and the etiology is unclear. Here we presented a case of a 56-year-old known diabetic patient who developed jerky uncoordinated involuntary movements of the lower limbs with flexion at the hips after administration of spinal anaesthesia. These movements lasted 2-3 minutes, occurring without any form of stimulation in the limbs despite loss of sensation to the lower limbs. He was treated with iv ondansetron 8mg, iv hydrocortisone 200mg, iv chlorpheniramine 10mg. Symptoms improved after about 3 hours after induction of spinal anaesthesia with return sensory and purposeful motor function of the lower limbs. Involuntary movements of the lower limbs can occur unexpectedly following spinal anaesthesia in a diabetic patient. Anaesthestist should be mindful of this and be ready to manage the situation when it arises.