In DCE-MRI, the effect of the r2* relaxivity of gadolinium-based contrast agents is often assumed to be negligible. Here, the validity of this assumption at 7T was tested. DCE-MRI was performed on two preclinical cancer models using a spoiled multiple gradient-echo acquisition, which enabled correction for transverse relaxation. Not accounting for R2* resulted in underestimation of the Tofts pharmacokinetic parameters, with Ktrans being the most affected and vp the least. Simulations showed that the R2* effect can be significant even at 3T in highly perfused regions but can be mitigated by decreasing TE and TR or increasing the flip angle.