A womanâs vagina normally has a mild odor, but inflammation or infection of the vagina or cervix can result in an unusually strong, persistent or bad vaginal smell that is often described as a fish-like odor. Vaginal odor can result from a variety of conditions and diseases that include:Overgrowth and imbalance of certain microorganisms, such as bacteria or yeast that normally live in the vagina in a certain balance. This is called bacterial vaginosis.Sexually transmitted diseases.The most common cause of vaginal odor is bacterial vaginosis (BV), which is characterized by an overgrowth of certain bacteria in the vagina. In most cases, BV does not lead to complications, but it can increase a womanâs chances of developing a sexually transmitted disease.aginal odor can result from a variety of conditions and diseases that include: Overgrowth and imbalance of certain microorganisms, such as bacteria or yeast that normally live in the vagina in a certain balance. This is called bacterial vaginosis. Sexually transmitted diseases.