In the present work we studied the thermophilic biological treatability of high strength liquid wastes from a pharmaceutical industry (rich in organic matter – COD: Chemical Oxygen Demand, nutrients and salinity). Different mixtures (with concentrations of COD, phosphorus and chloride up to 57,000 mg L −1 , 2000 mg L −1 and 9000 mg L −1 , respectively) were tested. The pilot plant used in this work was designed and built with dimensions comparable to a semi-industrial unit. The results are therefore representative for full-scale applications. During four months of experimentation, the pilot plant (TAMR – Thermophilic Aerobic Membrane Reactor) was operated at 49 ± 1 °C and the organic loading rate was 1.5–5.5 kg COD m −3 d −1 with a hydraulic retention time of 5–10 days.Main results are the following: a) extremely high COD removal rate (up to 98%); b) very low sludge production (∼0.016 kg VSS produced kg COD removed −1 ); c) suitability as a pre-treatment to a conventional (e.g. activated sludge) biological treatment (the studied pharmaceutical industrial wastewaters are discharged into the sewer system for final polishing in a centralized municipal wastewater treatment plant) and d) high phosphorus removal (up to 99%).