Guidelines for pre-clinical ASL are lacking. We propose MRI parameters for the use of pseudo-continuous ASL in rats. Carotid artery velocity was determined in three rat strains. Bloch simulations for ASL with this information and with parameters for pre-clinical scanners were used to determine the optimal width of the tagging plane required for blood inversion in this smaller species. The use of multiple post-label delays (PLD) in ASL-MRI generated blood arrival maps indicating that a PLD of 550ms was sufficient. Validation of CBF maps generated from ASL was performed using autoradiography, the current gold-standard technique for pre-clinical perfusion measurement.