The present application relates to a process for purification of a bacterial cytolysin comprising the steps of a) growing a culture of cells expressing bacterial cytolysin, b) mechanically breaking the culture of cells to form an extract, c) prefiltering the extract, d) binding soluble aggregated bacterial cytolysin contained in the extract in the presence of detergent to a hydrophobic interaction chromatography material under high salt (preferably 0.6-2M salt) conditions, and e) eluting bacterial cytolysin in the presence of detergent under low salt (preferably 0-0.2M salt) conditions.