An optical information-recording medium having in-groove pits, which is excellent in recording and reproduction characteristics and tracking characteristics, is provided. A method for producing the optical information-recording medium is also provided. Further, a stamper to be used for producing a substrate for the optical information-recording medium and a method for producing the same are also provided. In the optical information-recording medium of the present invention, the in-groove pits, which have flat bottom surfaces, are arranged on a groove which has a flat bottom surface. Therefore, it is possible to increase the difference between a height position of an interface between a recording layer and a reflective layer at a groove portion formed with the recording layer containing an organic dye and a height position of the interface between the recording layer and the reflective layer at an in-groove pit portion, as compared with an optical information-recording medium in which a wide-width portion and a narrow-width portion are formed on a groove. Accordingly, information, which is recorded on the in-groove pits, can be reproduced at a high modulation factor and at a low jitter.