We describe a patient with Guillain-Barré syndrome (GBS) following Campylobacter jejuni enteritis, accompanied with severe cramping pain and a marked increase in serum creatine kinase (CK) levels. Both conditions became evident three weeks after the onset of GBS and continued for longer than one month. In this patient, it is possible that rapid extensive denervation due to severe axonal degeneration of motor nerve terminals might have caused hyperexcitability in regional muscles, leading to recurrent muscle cramps and persistent release of muscular CK.