A 34-year-old woman with a history of chronic foot pain was admitted for bone evaluation. Bone scan revealed focal foot uptake in the early and late images. SPECT images combined with low dose CT revealed uptake at the site of a nidus considered to be osteoid osteoma. CT images are usually used for attenuation correction in SPECT, to improve anatomic localization and for precise morphologic information. This case demonstrated that fusion of the SPECT and CT images was useful to arrive at a rapid diagnosis of osteoid osteoma.