An interface device for an optical recording and/or reproducing apparatus for recording and playback of an optical disc, wherein the configuration of an interface circuit between a pickup that reads and writes information from/on the optical disc and a radio frequency (RF) integrated circuit (IC) for signal processing is simplified. To this end, the interface device includes a pickup, an integrated circuit, and a multiplexer. The pickup drives a plurality of laser diodes generating laser signals to record and/or reproduce information on a plurality of discs, respectively, and receives the laser signals reflected from the discs and output photodiode (PD) signals corresponding respectively to the received laser signals. The integrated circuit controls outputs of the laser diodes, and processes the PD signals from the pickup. The multiplexer is disposed in the pickup, and selects a PD signal corresponding to a particular one of the discs from among the PD signals from the pickup and interface the selected particular PD signal to the integrated circuit.