The Optical Fibre Sensors (OFS)-based monitoring of a composite part during its manufacturing process is presented. The sensor is made of a dual grating, i.e. a standard FBG and a Long Period Grating (LPG) photo-written at the same location, which provides accurate temperature and strain measurements, as well as a good spatial resolution. By using the differences of sensitivities of each grating, this dual-sensor is able to discriminate and to determine accurately temperature and strain. The dual-sensor has been tested during the curing of a pure epoxy resin, and a composite part obtained by Liquid Resin Infusion (LRI) process. Such dual-grating sensor is also very promising for SHM of composite parts.