A Laser Doppler Anemometer and a capillary rheometer are used to study the nature of emerging jets of liquid paraffin and a highly elastic solution of Separan Ap30. In particular, the effect of die entry instabilities reported earlier for the polymer solution is studied. Velocity profile measurements are made in the ranges550⩽γ⩽2176 sec−1,L/D=26.3,for liquid paraffin and24.5⩽γ⩽489 sec−1,26.3⩽L/D⩽52.6,for the polymer solution. Surface velocity measurements for the polymer solution in the above range show that the propagation of spiralling instabilities results in a transverse wave‐like phenomenon which causes distortion of the jet diameter at die swell. The distortion increases with increasing shear rates and decreasing tubeL/Dratios. Data forL/D=26.3are presented and the results for the polymer solution are discussed in relation to the reported extrudate distortions in polymer melts. A mechanism for the occurrence of matte and sharkshin extrudates is proposed.