Transient lateral patellar dislocation is a commonly encountered injury. It presents a challenge to the radiologist due to the difficulty with making the correct diagnosis on radiography. The MR findings of acute transient lateral patellar dislocation have been well described1–3 and include rupture of the medial patellofemoral ligament, large knee effusion, “kissing bone contusions” in the medial facet of the patella and lateral aspect of the lateral femoral condyle, lateral patellar tilt or subluxation, osteochondral fracture of the patella and/or the lateral femoral condyle, and intra-articular bony fragment. There is only one report in the literature on the radiographic diagnosis of transient lateral patellar dislocation.4 Diagnosing transient lateral patellar dislocation on radiography is challenging because its imaging features on radiography are subtle. Looking for these small findings is similar to looking at the tip of an iceberg: The small visible tip at the surface harbors serious danger down below! This CME article reviews the salient aspects of transient lateral patellar dislocation relevant to daily radiology practice.