Prostate cancer (PC), which has high morbidity and mortality among elderly men, is becoming the most common malignancy in men. The progression of PC is associated with several aspects including apoptosis, proliferation and metastasis. C-Jun N-terminal kinase (JNK) is a member of mitogen-activated protein kinases (MAPKs), which play vital roles in regulating diverse cell processes. JNK has been shown to activate multiple substrates to modulate apoptosis, proliferation, tumorigenesis and inflammation in response to various stimuli including cytokines, pathogens, growth factors, oxidative stress, ultraviolet radiation, toxins and drugs. In addition, emerging evidence has indicated the significant roles of androgen receptor in prostate cancer development. In this review, we will summarize our current knowledge on the roles of JNK in the apoptosis, proliferation, migration and DNA repair as well as dissect the relationships between JNK and androgen receptor in prostate cancer. Chemotherapeutic drugs targeting JNK will also be discussed, possibly providing an overview on the development of therapeutic strategies.