Giant cell tumor (GCT) of the craniofacial bones has been reported but they are not common. This tumor occurs more often in women than in men and predominantly affects patients around the third to fifth decade of life. GCTs are generally benign but can be locally aggressive as well. We report a case of GCT involving the temporomandibular joint (TMJ), which was initially thought to be temporomandibular disorder (TMD). A 22-year-old female presented with swelling and pain over the right temporal region for 18 months associated with jaw locking and clicking sounds. On examination, her jaw deviated to the right during opening and there was a 2×2 cm swelling over the right temporal region. Despite routine treatment for TMD, the swelling increased in size. Computed tomography and magnetic resonance imaging of the brain and TMJ revealed an erosive tumor of the temporal bone involving the TMJ which was displacing the temporal lobe. Surgical excision was done and the tumor removed completely. Histopathological examination was consistent with a GCT. No clinical or radiological recurrence was detected 10 months post-surgery.