UNASSIGNED : Acute traumatic patella dislocations are common injuries seen in emergency departments. We present a rare injury which involves an acute, irreducible intra-articular dislocation of the patella. In this particular case, we describe a horizontal type intra-articular dislocation of the patella in a 66-year-old lady, which was complicated by impaction into the distal femur. She underwent two failed closed reduction attempts, but subsequently reduced spontaneously on the orthopaedic floor as she was waiting for an open reduction in the operating room. CONCLUSIONS : The management of acute patellar dislocations can be divided into closed and open reduction methods. In cases where a closed reduction is unsuccessful, an open reduction under general anesthesia may be pertinent to treat this acute condition. CONCLUSIONS : We report a case of an intra-articular patella dislocation which has shown that spontaneous reduction is possible for cases following unsuccessful initial closed reduction, yet it still remains unadvisable to delay open reduction. We highlight, through this case, the importance of maintaining a high index of suspicion for these uncommon injuries.