Crude oil characterization by infrared (IR) spectroscopy and whole oil gas chromatography (GC) has been used to provide data for establishing multivariate prediction models for physical properties of crude oils. The parameters of interest are used in multiphase flowmeters (MFMs) for monitoring production and transport of petroleum fluids, and permittivity parameters are of special interest. Data for 20 crude oils and condensates has been acquired and modeled using partial least squares (PLS) modeling. Good quality predictions were obtained for density, velocity of sound, and static and high frequency permittivity. Biodegradation of crude oil is the main cause of variation in the modeled variables. The data required are obtained in standard analytical procedures, and thus the approach has a considerable potential for use in on-site quality assurance.