A process for preparing an organic hydroperoxide, which process comprises: (a) oxidizing an organic compound to obtain an organic reaction product containing organic hydroperoxide; (b) mixing at least part of the organic reaction product of step (a) with a basic aqueous solution to obtain a mixture of basic aqueous solution and the organic reaction product; (c) separating the mixture of step (b) to obtain a separated organic phase containing organic hydroperoxide, and a separated aqueous phase; (d) mixing at least part of the separated organic phase of step (c) with water to obtain a mixture of an aqueous phase and the organic phase; and (e) separating the mixture of step (d) to obtain a separated organic phase containing organic hydroperoxide, and a separated aqueous phase; in which process the separation to a separated organic phase and a separated aqueous phase in step (e) is carried out with the help of a coalescer containing glass fibers.