At least two general hypotheses have been proposed to explain microlith function in Australia. Recent residue studies of Australian microliths, commonly called backed microliths, suggest that these small stone tools were hafted and used in a variety of tasks but lack compelling evidence of use as spear tips or barbs (Hiscock et al. 2011). In contrast, earlier studies have supported Johan Kamminga’s conclusion that, on the balance of evidence, Australian microliths were “primarily the penetrating or lacerating elements of composite spears” (Kamminga 1980: 11). I argue that it is premature to reject either of these hypotheses, and argue that current evidence for microlith function is consistent with a limited range of composite tool forms including elements in spears and multi-purpose knives.