ChAdOx1 nCoV-19 is an effective and well-tolerated coronavirus disease 2019 
(COVID-19) vaccine. Rare cases of serious adverse events have been reported with 
this vaccine. We report three patients who developed Guillain-Barré syndrome 
following ChAdOx1 nCoV-19 vaccination, who did not have active or prior COVID-19 
infection. The neurological illness in all patients had an onset of 11-13 days 
after the first dose of vaccine. All were characterized by sensorimotor weakness 
of the upper and lower limbs, with facial diplegia in one and dysautonomia in 
the other. Nerve conduction studies were consistent with demyelination in two 
and axonopathy in one. Cerebrospinal fluid analysis showed albuminocytological 
dissociation in two patients. All patients had moderate-to-severe disability. 
They were treated with intravenous immunoglobulin, with stabilization of the 
disease. Proper monitoring and prompt reporting of such cases is required to 
ensure safety of the vaccine.