Doubts about the attribution of the Trinil femur to Homo erectus on anatomical grounds have a long history. Here, for the first time, published stratigraphic information and chemical evidence based on the Ca/P ratios confirm that the anatomical doubts are justified. The Trinil femur apparently belongs to a more recent stratum above the `fossil layer' (Hauptknochenschicht, HK) in which the Trinil calotte was found. It is concluded that the Trinil Femur I belongs to Homo sapiens, whereas the Trinil Femora II-V and the calotte belong to H. erectus. The chemical evidence derives from the use of electron probe energy dispersive X-ray microanalysis (EDXA), a technique that can be virtually non-destructive and therefore may be used on scarce fossil evidence.