Green mucus vaginal discharge is an abnormal feminine secretion that occurs for some reasons. Most of the time, the discharge is yellow-green, has a bad smell that’s usually referred to as fishy, and a thick, creamy consistency that resembles cottage cheese. Common causes include sexually transmitted diseases (STDs), bacterial vaginosis, and foreign objects inside of the vagina (e.g. tampons). Many women may experience odorless green discharge as a normal part of their menstrual cycle, which isn’t necessarily a reason of concern.