Arising from detailed reassessment of field work in the area of Ny Friesland and Olav V Land from 1938 to 1965, a revised stratigraphical scheme is proposed for the Hecla Hoek succession which is known to range downward from lower Ordovician and lower Cambrian (1 km.) into a relatively unbroken sequence of Pre-Cambrian rocks about 19 km. thick. The metamorphosed older rocks, previously grouped as lower Hecla Hoek, are reinterpreted as a succession 12 km. thick with a large volcanic component and a distinctive tillite horizon. Correlation is attempted anew with rocks elsewhere in Spitsbergen and overseas. The Hecla Hoek suite contributes to an interpretation of the development of the Caledonian tectonic province in late Pre-Cambrian and lower Palaeozoic time.