The elongation viscosity of linear low density polyethylene and low density polyethylene were estimated using converging flow and stagnation flow devices. Results were obtained from the converging flow rheometer using the analyses proposed by Binding [1] and Cogswell [2]. These results were compared with an estimate of uniaxial elongation viscosity obtained with the stagnation flow rheometer similar to that proposed by Mackay et al. [3]. The results show that the elongation viscosities determined by both flow geometries are comparable. Also, the measured elongation viscosity is affected to a small degree by geometric properties for converging flow.