Histamine h3 receptor (H3R) is expressed in numerous types of tumor and is associated with tumor cell proliferation, migration and invasion. However, whether H3R is expressed in prostate cancer remains unknown. Therefore, the expression and function of H3R in prostate cancer was investigated. Immunohistochemistry, reverse transcription-quantitative polymerase chain reaction and western blotting all indicated overexpression of H3R in prostate cancer. Cell counting kit-8 (CCK-8), migration and invasion assays demonstrated that overexpressed H3R is associated with cell proliferation, migration and invasion. Inhibition of H3R induced cell apoptosis, however, androgen receptor protein expression was decreased. Overall, the results suggest that H3R is overexpressed in prostate cancer and associated with cell proliferation, migration and invasion. These results may broaden our understanding of the underlying pathological mechanisms of prostate cancer and aid the discovery of novel treatments for prostate cancer. These findings suggest that inhibition of H3R may have favorable application prospects in the treatment of prostate cancer.