A microcomputer-based automated spinal cord monitoring system was developed and 56 spinal operations have been carried out with it since 1986. The system comprises an electrodiagnostic system (Dantec 2000M), an FM tape recorder, a channel selector, an electrical relay, a Modem and a microcomputer which controls all of the elements. The program allowed for automated recording and analysis of evoked potentials during spinal surgery and alarm signals were generated according to the criteria of amplitude decrease and latency delay. It was demonstrated that automated spinal cord monitoring in the operating room was performed easily, reliably and safely allowing the surgeon to react quickly to possible compromise of the spinal cord. The design and usefulness of the system is described in this report.