Localized prostate cancer does not cause any symptoms. Until the development of the PSA blood test, detection of localized prostate cancer could only occur if the cancer grew to the point where it was able to be felt on digital rectal examination or if it was found incidentally during transurethral resection of the prostate for presumed benign enlargement.

Prostate cancer that has metastasized may cause pain, especially from spread to the bones. Weakness from anemia may occur if prostate cancer has affected multiple areas of the bone marrow, limiting the body's ability to produce red blood cells. In advanced cases, enlargement of lymph nodes in the pelvis can obstruct urine flow, resulting in backup of urine in the kidneys (hydronephrosis) with possible kidney failure if this process affects both kidneys.

Locally advanced prostate cancers may obstruct urinary flow and/or cause severe irritation in the bladder region when the cancer extends from the prostate into the base of the bladder. Treatment of this locally advanced cancer can be very difficult. Obstruction to urinary flow may be opened by transurethral resection of the prostate, but there is a delicate balance between opening the urethra adequately to void and opening the urine passage too much, resulting in incontinence. Fortunately, there appear to be fewer men presenting with locally advanced cancers, possibly because of the more active and frequent application of local treatments with earlier detection of prostate cancer. This change in detection occured primarily in the late 1980s and early 1990s with widespread application of the PSA blood test.