Collagen degradation occurs during various physiological and pathological conditions. However, only a limited number of proteases with unique characteristics can trigger collagen degradation. Until recently, practical applications of collagenolytic proteases from bacteria had not been considered because their functions in bacteria are closely related to pathogenicity. However, bacterial collagenolytic proteases have many interesting and useful features. This review focuses on the collagenolytic proteases from bacteria, in particular their molecular properties and practical applications.