Recent literature comparing the effectiveness of above-elbow and below-elbow plaster casts appears to suggest that either cast type offers adequate immobilization for distal radius and ulna fractures. The idea that an appropriate mold placed on the cast is the most significant determinant of successful immobilization and, thereby, patient outcome has also been elucidated. The purpose of this study was to compare the effectiveness of above-elbow versus below-elbow fiberglass casts in maintaining distal radius/ulna fracture reduction and to identify factors associated with treatment failures.