For evaluation of potential functional deficits, an intraarterial amobarbital test is performed prior to neurosurgical or neuroradiological interventions. To visualize individual amobarbital perfusion patterns, simultaneous injection of 99mTc-HMPAO was performed previously. The present study describes for the first time a method of coregistration of intraarterial SPECT during selective amobarbital test to MRI. Three patients undergoing selective amobarbital test of the posterior cerebral artery were included. SATSCOM (Selective amobarbital test intraarterial SPECT coregistered to MRI) was performed by skull extraction in SPECT and MRI followed by surface matching. In all three patients, SATSCOM revealed accurate matching results. With this functional–anatomical mapping, suppression of higher cortical functions can be correlated to anatomical regions. Furthermore, a more precise mapping of amobarbital effect improves planning invasive interventions, particularly those close to eloquent areas.