The authors report their experience in the implantation of hepatic metastases in rat, for research in magnetic resonance (MR) imaging. Tumor cells were directly injected with a fine needle into an hepatic lobe, after enzymatic disaggregation of the cell suspension. Cryopreservation of the cell line is possible after the above-mentioned preparation. Tumor implants were observed in all the 20 animals studied, with size varying from 0.5 to 2.7 cm, according to the time elapsed between inoculation and sacrifice of the rat. On MR imaging the tumors presented the same signal intensity as the corresponding human pathology, on both T1- and T2-weighted sequences. The animal model can be used for the evaluation of the efficacy of MR imaging of the liver, and mainly for the assessment of new organo-specific contrast agents.