AbstractPenicillin V and/or G were extracted from fermentation broth by Amberlite LA‐2 in n‐butylacetate at pH 5 in a laboratory centrifugal extractor, Type SA 01 of Westfalia, up to an overall phase throughput rate of 30 L/h, in a bench‐scale four‐stage extraction system, consisting of Type TA 1 of Westfalia, up to an overall phase throughput rate of 110 L/h, and in a pilot‐plant three‐stage extraction unit, consisting of Type TA 7 extractors of Westfalia, up to a phase throughput rate of 990 L/h with very high degrees of extraction (up to 99%). The reextraction from the ion‐pair complex, which contained organic solvent, was performed by phosphate, borate, or carbonate buffer at pH 7.5–8.5 in all three extractor systems with degrees of extraction up to 98%, but at considerably lower overall phase throughput rates than those of the extraction, since no satisfactory phase separation is possible at higher throughput rates.