A continuous record of ground tilt was obtained at a site 1.15 km west of the active crater during the 1973 eruption in Heimaey, Westman Island. An uplift corresponding to a tilt value of approximately 200 μrad persisted through the active period of the eruption and was followed by rapid subsidence near the end of volcanic activity. Large spasmodic tilt surges superimposed on the general uplift seemed to be poorly correlated with volcanic, or seismic, activity. They may have been due to localized infiltration of shallow fractures by lava or gases, whereas the more gradual and moderate changes in tilt level resulted from the rise and decay of pressure in a deep-seated source.