To examine the possible relationship between anti-centromere antibodies (ACA) and pediatric rheumatologic diseases, we investigated the presence of ACA (using enzyme immunoassay) in the sera of 45 children and adolescents with such diseases and compared the results with a group of 42 age- and gender-matched healthy subjects. ACA were present ( > or =10 U/ml) in three out of five patients (60%) with scleroderma (SCD), in seven out of 16 (43.8%) patients with systemic lupus erythematosus (SLE), in two out of five patients (40%) with mixed connective tissue disease (MCTD), in one out of four patients (25%) with dermatomyositis (DMS), and in two out of 14 patients (14.3%) with juvenile rheumatoid arthritis (JRA). ACA were also detected in a single patient with anti-phospholipid syndrome (APL) who had digital gangrene and hemiparesis, as well as in two healthy subjects. ACA positivity was related to the presence of Raynaud's phenomenon in the studied sample, as 86% of patients suffering from the phenomenon were ACA positive. ACA positivity was associated with older age, high blood pressure and high erythrocyte sedimentation rate (ESR) values, and lower hemoglobin and weight and height percentile values. It was also higher among anti-nuclear antibody-positive subjects. Raynaud's phenomenon and ACA positivity shared almost the same clinical and laboratory associations in the studied patients. Thus, ACA are probably among the markers of Raynaud's phenomenon in pediatric rheumatologic diseases. Their value as predictors of future development of the phenomenon needs further evaluation.