Pathogenic variants in nucleotide-binding oligomerization-like receptor protein 12 (NLRP12) have been recently suggested as possible causes of autoinflammatory syndromes and should be considered for the differential diagnosis in the patients presenting with symptoms of autoinflammatory diseases. Here we report a very rare case of NLRP12-associated autoinflammatory disease patient who initially presented with polyarthritis and was diagnosed as FMF. Later, the genetic analysis excluded many autoinflammatory conditions including FMF and revealed a c.1206C>G; p.(Phe402Leu) variant in the NLRP12 gene. Awareness of rare autoinflammatory conditions is important to have the best approach to the patients presenting with common symptoms of autoinflammatory diseases.