A dual blade retractable seam ripper is provided. The seam ripper has a generally cylindrical tube and a unitary injection molded slide block structure. The tube has a control slot and two capped ends with blade extension openings, one major and one minor. The unitary structure has a major seam ripping blade and a minor seam ripping blade, each carried by a support. Each blade projects through the corresponding cap opening. One support is attached to a leaf spring cantilevered at the other end. The spring carries a control button which projects through and moves within the slot and a locking pin which extends beyond the spring. Depressions in the tube engage and dis-engage with the locking pin as the button moves and is pressed.