Among the raw materials which travel in naves onorariae, whithout a doubt was the Sicilian sulphur. The territory of Agrigento can be presented, for a longtime, as the central place for intense trading exchange in sulphur, which served in agriculture, medicine, wool purification, at war for preparing weapons, and for many others domestic uses. Unlike others goods, as raw materials (lead, iron, wood, marmor), the archaeology of sulfur and its production areas canno’t rely, as for wine and oil, on the study of the containers in which the product travelled. The paper explains the whole situation and presents some important artefacts, the tegulae sulphuris, which are for now the sole fossile guides, awaiting thorough stratigraphical researches on ancient sulphur explotations we have already identified, which will be useful in the study of that important field of the Roman economy. Last, we focus on trading associations, especially that of the Annii and the Atinii, also documented in the sulphur industry.