Rheological properties of aqueous polyacrylamide solutions have been measured in shear and extensional hows. Elongational viscosity measurements were performed with an opposed-nozzles stressmeter. The FENE-P constitutive model is used for describing the rheological properties of the solution. A single relaxation time is sufficient to give satisfactory agreement between the FENE-P model and the measured properties. In view of the fact that the how in the opposing jets device is not purely extensional, a numerical simulation of the flow is made in order to interpret experimental results.