Dynamic contrast enhancement (DCE) MRI is an important clinical imaging tool to characterize hepatic tumors. Especially in combination with PET imaging data, it has been shown to improve diagnostic confidence compared to PET/CT. Nevertheless, respiratory motion is still challenging, requiring multiple breathholds and leading to low scan efficiencies for PET and MR. Here we present a motion-corrected simultaneous DCE-MRI/PET approach which enables imaging with 100% scan efficiency using all data, to improve PET quantification and accurate alignment between both modalities. The proposed technique was evaluated in three patients with hepatic lesions showing an increased contrast-to-noise-ratio of PET tracer uptake by more than 80%.