Fiber optic data transmission already has led to revolutionary developments, and ongoing research in fiber optic sensing technology for applications in extreme operational conditions will boost the development of fiber optic multipleparameter sensing systems further. Such innovations will be of particular benefit to the oil and gas industry in situations where conventional electronic sensors are not technically feasible or cost efficient. It was an eye opener for the oil and gas industry when fiber optic-based distributed temperature sensing was introduced two decades ago. Suddenly, temperature profiles over the entire length of the wellbore could be monitored to deliver data for troubleshooting and production optimization. Judging the speed of developments today, a second fiber optic sensing revolution can be expected in the oil and gas industry in the near future. In the multiparameter sensing systems of the future, different types of fiber optic sensors (flow, pressure, acoustic, chemical, vibration, gravity, etc.) can be manufactured and read through a single optical fiber. Data from the different types of sensors will be merged and processed through special data mining algorithms to generate unambiguous information for faster and better decision making.