Several antibiotics such as erythromycin, oxytetracyclin, benzylpenicillin, and actidione were extracted from aqueous buffers into reverse micellar solution of bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) in isooctane and recovered with high efficiency under mild conditions. Preliminary experiments with oxytetracycline dissolved in a fermentation broth indicate that the antibiotic can be selectively extracted from the broth and recovered efficiently without serious loss of potency.