In Adversus Colotem (1121F), Plutarch suggests that Colotes – in his polemical work against some of the eminent philosophers up to Epicurus – accused Arcesilaus of attributing his own sceptical views not only to Socrates and Plato but also to Parmenides and Heraclitus. Since Colotes’ list dated back to Arcesilaus’ time, it seems likely that Colotes derived the list from Arcesilaus himself. However, Heraclitus does not figure at all among Arcesilaus’ illustrious predecessors in Cicero’s Academica. This absence is puzzling not only because Heraclitus had a ‘pervasive impact’ upon Plato’s philosophy, and because Arcesilaus strongly appealed to Plato, but also because Heraclitus was a key figure for the Stoics exactly at the time of Arcesilaus and Arcesilaus’ quarrel with the Stoics over their philosophical predecessors. I will set out to detect if and to what extent Arcesilaus made use of Heraclitus in his own philosophy.