Inside the front cover of the manuscript Ambr. B 7 inf. (= gr. 837), which contains Aristotle’s Physics and De anima, there are two partly erased ex-libris which prove that it belonged to Aldus Manutius. This paper proposes a reconstruction of its history from traces left by 15th and 16th century readers (George Scholarios, Lauro Quirini, Nicholas Byzantios, Aldus Manutius, Justin Dekadyos, G.V. Pinelli and Michael Sophianos). Further, ink stains and finger-prints invite the inference that the manuscript was used in the printing press during the preparation of the second of the five volumes of the Aldine Aristotle (1495-98).