Penile discharge is the abnormal loss of fluid that is not urine or semen from the urethra (urine tube) at the tip of the penis.

It is commonly the sign of a sexually transmitted disease (STD), and it requires prompt and accurate diagnosis and treatment, usually by staff at a specialist genitourinary medicine (GUM) or STD clinic.

The discharge is often accompanied by other symptoms such as:
- Burning on passing urine (dysuria)
- Frequent need to pass urine (frequency)
- Excessive need to urinate at night (nocturia)
- Rash in the genital area, which can be painful or itchy
- Swollen lymph nodes (glands) in the groin.

Common causes of penile discharge are:
- Gonococcal urethritis. Discharge occurs in 95 per cent of men and is purulent in 75 per cent, white or cloudy in 10 per cent and clear in 5 per cent. Recent urination can make the discharge appear less purulent. When the infection begins to resolve, the discharge changes from purulent to mucoid (mucus-like).
- Non-gonococcal or non-specific urethritis (NGU,NSU). Several different organisms ('bugs') can cause the syndrome:
   Chlamydia trachomatis (25 to 60 per cent).
   Mycoplasma genitalium (up to 25 per cent).
   Ureaplasma urealyticum (15 to 25 per cent).
   Trichomonas vaginalis (17 per cent).
   Herpes simplex (rarely).
- Prostatitis. Whitish discharge from penis often occurs with urinary discomfort or pain, lower abdominal pain, testicular pain, burning sensation, bulge feeling around perineum area, etc.  
- Balanitis. Balanitis also causes redness, swell, rankle, boil, penis pain, fever, and weakness.