We report the use of susceptibility-weighted imaging (SWI) in detection of red nucleus (rubral) degeneration and atrophy in children with hypertrophic olivary degeneration (HOD) after posterior fossa tumor resection. The use of this modality for this particular application has not been previously described. Detection of red nucleus changes seems to be facilitated by the contrast mechanism of SWI over conventional MRI sequences. SWI can be considered in the evaluation of these patients and in the future might provide a means for further classification of patients with HOD and related symptomatology.