Although gas hydrates often occur in seismically active regions, the role of earthquakes as triggers of hydrocarbon seepage through gas hydrate-bearing sediments has been only super�cially addressed. The Makran continental margin o�shore Pakistan hosts hydrocarbon-laden sediments and gas hydrates and is prone to vigorous seismicity. The area was visited in the frame of RV METEOR expedition M 74/3 in 2007 (Bohrmann et al. 2008). Here we present geochemical evidence for a substantial increase in upward gas �ux inducing methane emission into the water column and gas hydrate formation in the sediment, a phenomenon which occurred within a few decades of the strongest earthquake ever reported for the entire Arabian Sea. We propose a causal relation and present re�ection seismic data supporting our hypothesis that co-seismic ground shaking induced mechanical fracturing of gas hydrate-bearing sediments creating pathways for free gas to migrate from a shallow reservoir within the gas hydrate stability zone into the water column. Our �ndings lead to conclude that hydrocarbon seepage triggered by earthquakes might play a role for carbon budgets at other seismically active continental margins. The newly identi�ed process presented here can help interpret data from similar sites.