Context :

Aims : We investigate the temporal spot evolution of the K-giant component in the RS CVn-type binary system \zeta Andromedae to establish its surface differential rotation .

Methods : Doppler imaging is used to study three slightly overlapping spectroscopic datasets , obtained independently at three different observing sites .
Each dataset covers one full stellar rotation with good phase coverage , and in total , results in a continuous coverage of almost three stellar rotations ( P _ { rot } = 17.8 d ) .
Therefore , these data are well suited for reconstructing surface temperature maps and studying temporal evolution in spot configurations .
Surface differential rotation is measured by the means of cross-correlation of all the possible image pairs .

Results : The individual Doppler reconstructions well agree in the revealed spot pattern , recovering numerous low latitude spots with temperature contrasts of up to \approx 1000 K with respect to the unspotted photosphere , and also an asymmetric polar cap which is diminishing with time .
Our detailed cross-correlation study consistently indicate solar-type differential rotation with an average surface shear \alpha \approx 0.055 , in agreement with former results .

Conclusions :