The behaviour of beef cattle is important for the safety and welfare of stockmen and animals. Ten microsatellites spanning BTA29 and, in addition, the candidate gene, dopamine receptor D4 gene, were analysed in 545 German Angus calves of six sires and included in a quantitative trait locus (QTL) study on the basis of three different behaviour tests. A putative QTL for the score while entering the scale (ScE) was detected at BMS764. The DRD4 fragment was mapped in the distal region of BTA29 15.3 cM distal of ILSTS081. The results clearly indicate that BTA29 with a putative QTL in the proximal part and the candidate gene, DRD4, in the distal part plays an important role in the regulation of temperament. During the study one of the sires was detected to be a blood chimera.