Marine smaller foraminifera from a 350 m thick, non-carbonate borehole succession are described from the upper Lower Triassic to lowermost Middle Triassic (Spathian–Lower Anisian) of offshore Western Australia. This is only the second foraminiferal fauna of this age described from the Southern Hemisphere and it differs from a coeval fauna previously described from the same area (Heath & Apthorpe, 1986). The new fauna contains some ‘Tethyan’ genera previously recorded from South China and the Alps, including Duostomina, Krikoumbilica, Gsollbergella, Trocholina, Endothyra and Endothyranella. Other genera and species appear to persist from the Permian. Three species are described as new: Dentalina septacosta, Krikoumbilica compressa and Trocholina planoconvexa. The age of the fauna is based on palynological evidence, correlated with conodont dating.