Chondromyxoid fibroma (CMF) of the rib is exceedingly unusual and few detailed image findings have been reported. Plain radiograph, computed tomography (CT), and magnetic resonance (MR) imaging findings and pathological aspects of a case of CMF of the right 2nd rib in a 15-year-old woman are reported, which was difficult to diagnose preoperatively. Though it is challenging to diagnose CMF preoperatively, it is important to be aware that CMF can exhibit atypical prominent exophytic features in unexpected locations such as the ribs.