The Atalanti Fault Zone in Central Greece is an area of high seismic risk, where destructive large magnitude earthquakes have taken place in the past. The microgravimetric network set up in the region to detect gravity changes associated with big tremors, has been monitored annually and the observations of the last five years, from 1981 to 1986, are presented here. All data were analyzed using a newly developed algorithm of network adjustment. Gravity changes of more than 40 μGal were detected after 1982 in the region between Atalanti and Arkitsa, and across the downthrow side of the fault. These gravity changes, implying uplift and observed only in this very closely monitored part of the network, increased gradually in 1983 and 1984 and declined in 1985. The inferred uplift may exceed 200 mm at the center of the bulge, applying the Bouguer gravity gradient of −0.2 μGal/mm. Examination of the water table data from wells in the region suggests that the amplitude of the observed gravity changes is not likely to have been caused by changes in the water level; only one third of the observed changes, at the most, could be thus accounted for. Since dilatancy cannot be established on the basis of the existing geophysical information there is no evidence for any association between the inferred uplift and the occurrence of a recent tremor in the region ( M l = 4.3 , June 6, 1986). However, it is possible that the aseismic movements monitored in the area after 1982, over a relatively small region in a small time-period, may offer some additional information about the deformation of the upper crustal layers. Another application of microgravimetry, as part of a multidisciplinary project, is being tried out on Santonni Island, which has one of the most active volcanoes in the Eastern Mediterranean. A network of 15 stations has been established there to try to detect upward movements of magma. It was set up in 1984 using three LaCoste and Romberg gravity meters and has been monitored annually since then. The rms error of adjustment was 7.0, 3.2 and 2.6 μGal, in 1984, 1985 and 1986, respectively. Small amplitude gravity changes were observed at spme stations in the network. Attempts to interpret these changes will be made if a clear pattern is confirmed by future observations and in the light of other available geophysical information.