Bladder pain syndrome (BPS) is an enigmatic condition, which can be debilitating for the patients, affecting their quality of life. Its prevalence is believed to have become markedly higher (100–300/100,000 women) than in previous years. Its etiology and pathogenesis remain unknown, and a number of theories based on clinical and experimental observations have been developed. It is difficult to be diagnosed and treated. There is a worldwide effort to standardize its nomenclature, definition, diagnosis, and treatment algorithm. The aim of this review is to critically appraise the current evidence on the diagnosis and management of BPS.