To evaluate the utility of bone scans for the follow-up of patients with small breast cancers (T less than or equal to 3 cm), the files for 133 patients whose disease was diagnosed between Jan. 1, 1979 and Dec. 31, 1980 were reviewed. At initial presentation, two of these patients already had bone metastases. During their disease course, 30 patients developed metastases and 16 of them had at least one bone metastasis. In 7 of these 16 cases, the bone metastasis was solitary; in 4 cases bone lesions were symptomatic. A total of 178 bone scans were performed during the follow-up of these 133 patients; 16 of these scans were positive, but only 4 examinations allowed the diagnosis of bone metastasis. Despite the slight prognostic value of initial bone scanning in this series, the technique is of little value unless it is combined with clinical examinations aimed at early detection of disease recurrence or metastasis. Except as part of clinical trial protocols, systematic bone scans appear unnecessary for the staging and follow-up of patients with small breast cancers.