Integrated quantum sources are proving to be the most effective technology of sources for scalable quantum applications. A platform that satisfies all the requirements has not prevailed yet. In this framework, we report, to the best of our knowledge, the first demonstration of a photon pair source in a silicon core fiber. The fiber, only 58 mm long, works at room temperature and shows an intrinsic brightness of 570 kHz/nm/mW(2) and a coincidence-to-accidental ratio of 133 +/- 2 at around 1.55 mu m wavelength. The low propagation losses of the platform, similar to 0.3 dB/cm in our source, pave the way for effective fiber-based quantum sources in the telecom band. A comparison with state-of-the-art further confirms the potential of this platform for future applications, especially in the field of quantum communication.