The present paper deals with compositional and microstructural features of 26 pre-Islamic, South Arabian coins recently unearthed during archaeological excavations. Most of the investigated coins come from Sumhuram (Khor Rori, southern Oman), and were minted by the Hadramawt kingdom (fourth century bc to third century ad); only a few of them belong to the Himyarite kingdom's coinage (first to fourth centuries ad). In addition, some coins of both the Hadramawt and the Himyarite kingdoms found at Qani' (B'ir ‘Ali, Republic of Yemen) have been analysed for comparison. Our main focus was to provide new hints towards the comprehension of the chronological evolution in South Arabian coinage in terms of both metal composition and minting techniques. In addition, some melting crucibles found at Sumhuram have been examined in an attempt to make a comparison with the coins’ composition and to test the hypothesis that they were used for minting operations.