The biodistribution pattern of [ 11 C]Kendine 91 (a novel HDAC inhibitor) after IV administration has been evaluated using Positron Emission Tomography (rats) and gamma counting of dissected tissues (rats and mice) at different doses (1μg/kg and 10.0mg/kg). Metabolism in mice plasma has been also investigated by radio-HPLC. Obtained results (fast accumulation in lungs, heart, kidneys and liver; lower uptake in pancreas and muscle) are in concordance with previously reported results using HPLC/MS-MS. Plasma analysis studies showed a fast metabolism of the radiotracer.