A longitudinal retrospective study of 37 patients previously tested for anticentromere antibodies (ACA) in 1982 was carried out. No ACA were found in stored sera from 22 ACA-negative patients including 1 patient with CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia). All ACA-positive patients, with 1 exception, were found to have ACA in their sera over prolonged periods of time. One patient developed ACA for the first time when the third feature of the CREST syndrome (Raynaud's phenomenon) was noted. Anticentromere antibodies were IgG, and no consistent change in titer over time was found.