The associations between the ability to metabolise glucose measured by the glucose tolerance test (GTT) and the estimated breeding values (EBVs) for milk performance in German Holstein sires were evaluated. The German Holstein sires born 1993 (n=43), 1998 (n=98), 1999 (n=104), 2000 (n=96), 2001 (n=91), 2002 (n=82), and 2003 (n=28) were analysed. The EBVs were taken from Vereinigte Informationssysteme Tierhaltung Verden. Statistical analyses were performed by General Linear Model and MIXED procedures, and phenotypic correlations among GTT and EBVs for milk performance were computed by the Pearson correlations. The sires born in 1993 had some significant (P<0.01) negative correlations between the milk yield and GTT, similarly for protein yield, but the majority of the correlations were non-significant (P>0.05). For the sires born in 1998–2003, the same correlation analysis resulted in non-significant and very low coefficients, few significant (P<0.05) correlations were found only for protein yield in year of birth 2000, protein percentage in year 2003, and for fat percentage and yield in year of birth 2002. GTT may be helpful for studying the metabolic capacity of dairy cattle; however, the possible use of GTT in breeding value prediction must be again clarified.