Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. PsA is often confused with other diseases such as osteoarthritis and rheumatoid arthritis. PsA involving temporomandibular joints (TMJs) are uncommon: only 19 articles with 43 cases have been documented in the literature. TMJ ankylosis caused by PsA is rare, with only six cases having been reported. The authors present four cases of ankylosis of the TMJ secondary to PsA and review the literature. The findings of this study suggest that more attention should be paid to psoriasis patients with TMJ symptoms and proper treatment should be taken to prevent irreversible TMJ damage.