The clinical manifestations of a patient with hereditary paroxysmal ataxia and neuromyotonia are described. Generalized tremor, triggered by sudden movements, and spasms of hand and foot muscles were the main clinical findings. Electromyogram (EMG) and nerve blocking studies led to the diagnosis of neuromyotonia. Treatment with acetozolamide was of no therapeutic value, confirming previous observations about the difference in response of paroxysmal ataxia with and without neuromyotonia.