In a process for producing phenol and/or cyclohexanone, benzene and hydrogen are contacted with a first catalyst in a hydroalkylation step to produce a first effluent stream comprising cyclohexylbenzene, cyclohexane, and unreacted benzene. At least part of the first effluent stream is supplied to a first separation system to divide the first effluent stream part into a cyclohexylbenzene-rich stream and a C6 product stream comprising unreacted benzene and cyclohexane.