Pomegranate juice consumption by a patient may be used to treat prostate cancer. Prior to the present invention, it has been observed that various pomegranate compositions have cancer chemopreventive properties on various in vitro treatment of human prostate cancer cell lines and in vivo treatment of human prostate cancer cell lines xenografted in athymic nude mice. Until the discovery of the present invention, it was not known if there is an efficacy for treating prostate cancer in human patient by any route of administration. The present invention provides a method of treating a subject with prostate cancer a composition comprising a therapeutically effective amount of an extract from pomegranate fruit. The extract of pomegranate may be a juice extract of pomegranate, an extract from inner or outer peel of pomegranate, or mixture thereof. Pomegranate juice may be used to treat subjects with rising serum PSA after prostate surgery or radiotherapy.