BACKGROUND: Progesterone is considered an endocrine disruptor chemical. It can be found in industrial discharges, municipal wastewaters, and, in some instances, even in treated effluents at the level of ng dm-3. RESULTS: Conductive diamond electrolysis can be used to remove progesterone from aqueous solutions. Increases in current density lead to less efficient processes, indicating mass transfer control of the process rate. Occurrence of chlorides in the electrolytic media favors the depletion of progesterone compared with sulphates, although it does not affect the mineralization rate. Independently of the solubilizing agent used, the process behaves similarly during a first stage of the electrolysis (at the four ranges of pollutant concentration studied). However, in a second stage, the rate changes abruptly due to reduced action of hydroxyl radicals in methanol media. CONCLUSIONS: Progesterone can be removed efficiently by conductive diamond electrolysis from aqueous solutions within the range of initial concentrations 10-2 to 102 mg dm-3. The process efficiency increases with the current density. Removal rate does not depend on the nature of the electrolyte, but this parameter affects the intermediates formed during the experiment. When pure methanol is used as solubilizing agent, only direct electro-oxidation takes place. Copyright (C) 2012 Society of Chemical Industry