The Åknes rockslide is a large, slow-moving landslide in Precambrian gneiss in Sunnylvsfjorden in western Norway. It has a volume of more than 50 million m3 and parts are moving at velocities of 2–8 cm per year. If the sliding mass were to fall into the fjord, it would generate large tsunami waves. Given the hazard, a major site investigation was conducted and a monitoring program was established in cooperation with a number of national and international groups. The monitoring program integrated a variety of surface and subsurface instruments, including extensometers, crackmeters, tiltmeters, single lasers, GPS, total station, ground-based radar, geophones, climate station, and borehole inclinometers and piezometers. Reliable power and communications systems operate the instruments and transmit data. Movement data collected to date demonstrate continuous movement throughout the year, but with significant seasonal differences. During spring snowmelt and heavy precipitation events, the rate of movement can increase to 1 mm per day, which is 10 times the annual mean. Preliminary early-warning levels and associated actions have been implemented based on data from the Åknes rockslide and information on historic rockslides elsewhere in coastal Norway.