Optical fibers are finding a growing range of new applications in the petroleum industry, which include, not only those already well established in telecommunications, but also in novel sensing technologies. Possibility of dense multiplexing, continuous distributed measurements, long distances between measurement points and electronic circuits, and explosion risk free, are some of the characteristics shared by different types of optical fiber sensors. The major global oil and gas operators and service companies have elected optical fiber sensing as one of the key enablers to implement with all the expected functionality and reliability the novel technology of intelligent well completion. Continuous well monitoring allows the operator to access, at any time during the well life, important information regarding different process variables, such as pressure, temperature, flow-rate, pH, or even the position of sliding sleeves valves that control the flow through the well. This is part of the automation strategy to optimize production in the whole reservoir, a technological trend that points towards the concept of an intelligent oil field and that, in the near future, will be applied to the integrated management of production from several wells in the same reservoir, contributing to reduce intervention costs, and increasing recovery factors of fossil hydro-carbon reserves. The present work is inserted in this context, and reports the conception, development and results of tests conducted with prototypes of two different optical fiber transducers to be integrated in an intelligent well completion system. The first one is a Bragg grating differential pressure transducer, which has been developed to measure pressure drop across a Venturi flow-meter inserted in the production tubing. Test results with prototypes have demonstrated that the transducer may be applied to measure differential pressures in the range of more or less 5 bar, under static (average) pressures up to 21 MPa and temperatures below 90 Celsius Degree, with 0.06 percent full-scale resolution. The second development is a displacement transducer applied to measure the opening position of sliding sleeves valves. Two different measurement principles were investigated. The first, intended to general applications of displacement measurements, relied on the use of magnetostrictive actuators and fiber Bragg grating sensors. The second displacement transducer applies to a specific type of valve, which employs a mechanical spring to provide recovery forces to a hydraulic actuator. The proposed solution was based on the use of a load cell instrumented with fiber Bragg gratings. Tests results demonstrated that the prototype transducer was capable of resolving changes in displacement as lower as 0.03 mm in a full-range of 70 mm, approximately 0.04 percent full-scale resolution.