Abstract: The security manhole insert cover relates to a locking manhole insert to prevent ingress or egress to a manhole from above or below the manhole to prevent access to underground utilities, tunnels and underneath buildings and metropolitan areas to eliminate security intrusions and terrorist attacks by underground access, which would otherwise go undetected if access to the underground utility passages were not secured. The manhole insert cover has a cylindrical locking insert barring access to the engaging and disengaging mechanism required to remove the manhole insert cover and an integrated lower cover to prevent access to the engaging and disengaging mechanism from below, the insert cover adapted to fit within a manhole without required modification of the manhole and without detection of the insert cover having been installed from above ground levels.