Abstract: Geomorphological, sedimentological and structural observations demonstrate the rates of lateral propagation at both ends of the South Alkyonides Fault, a major active normal fault in the Gulf of Corinth, Greece. These data are used to study the temporal evolution of the displacement/length ratio of the fault. The South Alkyonides Fault has a surface trace of 38 km and a cumulative throw of 2.5–3.0 km. Palaeoseismology and geodesy show that the South Alkyonides Fault has a maximum displacement rate of 2.6–4.7 mm a−1. Lateral propagation of the South Alkyonides Fault has systematically beheaded drainage, forming footwall wind gaps and enclosed hanging-wall basins. Dated marine and terrestrial sediments allow estimation of the timing of wind gap formation and rates of lateral propagation of the South Alkyonides Fault. The western and eastern ends of the South Alkyonides Fault have been propagating at 12.1–16.7 mm a−1 since c.0.33 Ma and <3.7 mm a−1 since 1.36 Ma, respectively. The summed rate of lateral propagation is 15.8–20.4 mm a−1. The value for the ratio of displacement rate-to-lateral propagation rate (0.13–0.30) over the last several hundred thousand years is higher than the ratio of cumulative displacement/length (0.07–0.12). Lateral propagation may have slowed relative to the displacement rate through time.