Concentration process of cucumber juice is an essential step in cucumber extracts and juice production in the industry in order to minimise the volume and weight for storage and handling purposes. Progressive freeze concentration (PFC) is a non-thermal concentration process that can be used in which water content in the juice will be frozen out in the form of an ice block layer by layer. The ice crystallisation process forms ice crystal lattice that rejects all impurities and in turn will leave behind highly concentrated cucumber juice. This research aimed to optimise the operating parameters involved in concentration of cucumber juice via PFC. The operating parameters involved were operation time, initial concentration, coolant temperature and speed of stirrer. Optimization of the PFC process was carried out with the effective partition constant, K as the indicator of the performance by using Response Surface Methodology (RSM) in STATISTICA software.