[en] The solvent extraction behaviour of Am(III) from dilute nitric acid media with sulfoxides (R₂SO) in Solvesso-100 has been investigated over a wide range of conditions. The very poor extractability of Am necessitated the use of salting-out agents, viz., nitrates of Al, Mg, Ca, Li and NH₄⁺. The effects of certain variables such as acidity, extractant concentration, salting-out agent, temperature etc., on metal extraction by sulfoxides have been examined systematically. For a fixed sulfoxides concentration, extraction attains a maximum value up to around 0.2-0.4M HNO₃ and decreasing above 1M HNO₃. In contrast, increasing the concentration of sulfoxide (0.8M DISO, 1.3M DBuSO) gives almost quantitative Am extraction up to 1M HNO₃. For satisfactory extraction, di-n-octyl as well as di-n-hexyl sulfoxide are the most suitable extracting agents. The extractability of Am increases with increasing amounts of all the salting-out agents studied and their effect follows the sequence: Al³⁺>Mg²⁺>Ca²⁺>Li⁺>NH₄⁺; this is also the relative dehydrating effect of the cations. The species extracted would appear to be Am(NO₃)₃x3R₂SO. Americium is easily stripped with 1-3M HNO₃ solutions from the loaded organic phase. The extraction decreases with increasing temperature, indicating the extraction to be exothermic. The extraction from partially non-aqueous solutions was also investigated. (author)