We report the case of a 54-year-old patient affected by ankylosing spondylitis who developed multifocal motor neuropathy with conduction blocks after 8 months of infliximab treatment. TNF alpha antagonist therapy has been associated with the development of both central nervous system and peripheral nervous system disorders, mainly of the demyelinating type. To our knowledge, this seems to be the second reported case of infliximab-related typical multifocal motor neuropathy with conduction blocks in which no other underlying causes of neuropathy were present. It is also the first in which typical multifocal motor neuropathy with conduction blocks spontaneously recovered without Ig.ev treatment and did not reappear over a long follow-up period. In our opinion, this strengthens the hypothesis of an actual adverse effect of infliximab in this patient. Finally, our case is the first one occurring in a patient with ankylosing spondylitis.