Pacemaker-induced hypotension has been utilized during 16 craniotomies for intracranial aneurysm. A background of moderate hypotension is provided by ganglionic blocking agents during the "approach phase" to the aneurysm. The need for pacemaker-induced hypotension may be signaled by sudden rupture of the aneurysm, or the desire to diminish the turgor, within a thin-walled aneurysm during the exposure. In all of these cases rapid hypotension was achieved with cardiac pacing allowing for definitive treatment in a relatively dry field. The one death occurred after inordinately prolonged and rapid pacing rates led to ventricular fibrillation, which can now be averted with the use of background ganglioplegic agents to induce initial moderate hypotension.