A multipurpose memory card adapter including a base and a cover. The base has first conductive pieces corresponding to connecting fingers of memory cards of Secure Digital (SD) card, Multimedia Card (MMC) and Reduced Size Multimedia Card (RS-MMC). A plurality of guide pieces is formed at a front end of the first conductive pieces to allow for a smooth insertion of the memory cards in position. The base further includes second conductive pieces corresponding to connecting fingers of mini SD card. A first end stop at which the mini SD card to be inserted into the base arrives is located at a farther position away from an insertion opening than a second end stop for the SD card and the MMC card. A side stop and a guide chamfer are formed between the first end stop and the second end stop. Meanwhile, a detecting piece and a write protection piece are provided at one side of the base. In addition, a plurality of mounting bosses is formed at the periphery of the base. The cover includes a plurality of mounting holes corresponding to the mounting bosses of the base as well as a grounding piece at a corner of both sides.