We describe a rare case of post-infective Acute Motor Axonal Neuropathy (AMAN) variant of Guillain-Barrè Syndrome (GBS) associated with myelitis and anti-GD1b positivity after SARS-CoV-2 infection. The patient referred to the hospital reporting a history of ten days lasting moderate fever, myalgia and anosmia, with the onset of progressive quadriparesis and ascending paraesthesias in the four limbs since five days from defervescence. A chest computed tomography demonstrated interstitial pneumonia with “ground glass opacities”, suggesting Coronavirus disease (COVID-19). The patient exhibited three negative reverse-transcription polymerase chain reaction (RT-PCR) nasopharyngeal swabs, while SARS-CoV-2 IgG was found in plasma. The electrophysiological examination demonstrated an AMAN and the spinal cord Magnetic Resonance Imaging (MRI) showed a T2-weighted hyperintense lesion in the posterior part of the spinal cord at the C7-D1 levels. Furthermore, anti-GD1b IgM was detected. GBS and myelitis could exceptionally develop simultaneously. Our findings reasonably support a causality link between COVID-19 and the neurological symptoms, suggesting a post-infective autoimmune reaction.