Flotation tailings dump material of the former lead-zinc mine near Freiberg (Germany) consists of fine grained quartz, feldspar, mica as well as the sulphide minerals pyrite, galena and sphalerite not recovered by flotation. Sphalerite contains, aside from iron, copper and cadmium, significant amounts of indium (up to 0.38% (w/w)) leading to indium contents up to 70 mg/kg in the mine tailings. Preliminary thermodynamic assessment showed a comparatively small Eh-pH-range where bioleaching is possible and indium is not hydrolytically precipitated. Shake flask bioleaching of original polymetallic sphalerite ore from the Freiberg mining district (400 mg/kg indium) showed maximum zinc and indium recovery rates of almost 100% or 80%, respectively. First bioleaching tests on tailings material achieved zinc and indium yields of up to 80%. A stepwise precipitation process is being developed for indium recovery from the PLS (pregnant leaching solution) consisting of combined iron/indium precipitation and subsequent processing of the indium pre-precipitate. (C) 2014 Elsevier Ltd. All rights reserved.