Although massive flank failure is fairly common in the evolution of volcanoes, measurements of flank movement indicative of instability are rare. Here 3‐D displacements from airborne radar amplitude images derived using an amplitude image pixel offset tracking technique show that the west and southwest flanks of Pacaya Volcano in Guatemala experienced large (~4 m), discrete landsliding that was ultimately aborted. Pixel offset tracking improved measurement recovery by nearly 50% over classic interferometric synthetic aperture radar techniques, providing unique measurements at the event. The 3‐D displacement field shows that the flank moved coherently downslope along a complex failure surface involving both rotational and along‐slope movement. Notably, the lack of continuous movement of the slide in the years leading up to the event emphasizes that active movement should not always be expected at volcanoes for which triggering factors (e.g., magmatic intrusions and eruptions) could precipitate sudden major flank instability. Key Points Three‐dimensional displacements of a volcanic landslide created using pixel offset measurements between two synthetic aperture radar amplitude images Four meters of flank movement at Pacaya Volcano suggest serious instability hazard Episodic movement initiated by rapid triggers may promote volcano edifice instability without timely warning