Overbank flood deposits of northern coastal Peru provide the potential for the development of a late Quaternary chronology of El Ni¿o events. Alluvial deposits from the 1982--1983 El Ni¿o event are the basis for establishing a type El Ni¿o deposit. Sedimentary structures suggesting depositional processes range from sheet flows to debris flows, with sheet flood deposits being the most common. The 1982--1983 deposits are characterized by a 50- to 100-cm-thick basal gravel, overlain by a 10- to 100-cm-thick silty sand bed and capped by a very thin layer of silt or clay. The surface of the deposit commonly displays the original shear flow lines crosscut by postdepositional mud cracks and footprints (human and animal). Stacked sequences of flood deposits are present in Pleistocene and Holocene alluvial fill, suggesting that El Ni¿o type events likely occurred throughout the late Quaternary. A relative chronology of the deposits is developed based on terrace and soil stratigraphy and on the degree of preservation of surficial features. A minimum of 15 El Ni¿o events occurred durning the Holocene; a minimum of 21 events occurred during the late Pleistocene. Timing of the Holocene events is bracketed by isochrons derived from the archaeologic stratigraphy. Corrected radiocarbon ages from included detrital wood provide the following absolute dates for El Ni¿o events: 1720¿60 A.D., 1460¿20 A.D., 1380¿140 A.D. (error overlaps with the A.D. 1460 event; these may represent a single event), and 1230¿60 B. C. ¿ American Geophysical Union 1987