Objective. To demonstrate the MR depiction of the intertrochanteric or femoral neck extension of fractures of the greater trochanter, when standard radiographs show only a fracture of the greater trochanter, Design and patients. A retrospective review was performed of the MR and radiographic findings in 13 consecutive patients (10 men, 3 women; ages 24-86 years) with radiographic evidence of fracture of the greater trochanter who were examined with MR imaging. Results. The MR study displayed the fracture of the greater trochanter in all cases. In all but three patients, MR examinations displayed an extension of the fracture into the intertrochanteric region, and in one, also an extension into the femoral neck, although the cortex at this level was not interrupted. Conclusion. When there is radiographic evidence of an isolated fracture of the greater trochanter, MR often shows an intertrochanteric or femoral neck extension of the fracture in both young and older adults. This finding may be a factor in determining the need for surgical intervention.