Ancient copper coins from Creek cities and confederacies such as Amphipolis, Veroia, Dion, Edessa, Magnetes, Stobi, Apollonia, Kerkyra, Pella, Philippoi, Phoenike, and the Macedonian and Thessalian Koina, were analyzed non-destructively by proton induced X-ray emission (PIXE) after removal of the patina. The copper coins were minted during Roman Imperial times (31 B.C.-268 A.D). Eleven elements were determined quantitatively. The correlation between the composition and the minting time is examined. The results are compared with those of a previous study for coins from the cities of Nikopolis in Epirus and Thessaloniki in Macedonia, in the same period.