Over the last 20 years, a number of multiphase flow measurement techniques have been developed for metering oil (or condensate) / water / gas commingled streams. The available techniques can be characterized as those that operate inline or with partial separation. The inline variety typically consists of several meters or measurements and a central computer to interpret the signals and calculate individual phase flow rates. Techniques that employ some element of separation typically use a compact, continuous mode gas-liquid separator with subsequent metering on the gas rich and liquid rich flow streams. This paper will review some of the more common techniques being used with a focus on the application of GLCC©s (gas-liquid cylindrical cyclones) in multiphase flow measurement