The Conference on „Optical Fibres and Their Applications” is held periodically in Poland since 1976, now every 18 months. It is organized alternately by two national optical fibre technological centres in Białystok (Technical University) and Lublin (UMCS University). The conference gathers interested persons from academic communities, technological, application, research and development, industrial, business, and administration ones, and summarizes periodic technical and application achievements of the involved national laboratories and enterprises, with participation of international guests. Since 1986, the conference is supported by SPIE – The International Society for Optics and Photonics via publications of their works in the series Proc. SPIE. The conference gathers usually around 150 participants and around 100 technical presentations. XVIIth conference on “Optical Fibres and Their Applications – OFTA 2017”, organized by Technical University of Białystok, was held in January 2017, and gathered similar number of persons and high quality papers. Topical area of the conference, which may be concisely determined as optical fibre photonics, embraced technology of active and passive optical fibres, active components cooperating with optical fibres as sources and detectors, optical fibre functional components, optical fibre sensors, optical fibre devices, circuits and systems – sensing, photonic signal processing, networked, and transmission. The article presents concisely a digest of chosen research and technical works presented during the XVIIth Conference on Optical Fibres and Their Applications.