Recent technological advancement of optical fibre sensing has led new ways in measuring the performance of geotechnical structures. The distributed sensing, namely Brillouin Optical Time Domain Analysis (BOTDA) is a novel technique of measuring strains in a continuous manner which has inherent distinct advantages over conventional point-based sensors. In bored pile instrumentation particularly, obtaining distributed strain profile is important when analysing the load-transfer and shaft friction of a pile, as well as detecting any anomalies in the strain regime. Features such as defective pile shaft necking, discontinuity of concrete, intrusion of foreign matter and improper toe formation due to contamination of concrete at base with soil particles, among others, may reduce the pile capacity. The objective of this article is to present one of the earliest deployed BOTDA optical fibre sensors in rock-socketing bored piles in Malaysia and share invaluable lessons learned from the instrumentation process. Data from the instrumented pile was used to estimate the shaft resistance of rock-socketing pile and issues related to locked-in stresses and creep are highlighted. Excellent agreement of strain measurements was recorded between fibre-optic sensors and vibrating wire strain gauges. © 2018 19th ICSMGE Secretariat. All rights reserved.