Viscoelastic flows of a PIB/PB/C14 polymer solution in axisymmetric cavity geometries have been studied. Multiple elastic flow transitions of spatial and temporal types are observed. The critical conditions for the onset of instabilities and the spatial and temporal structures of the flow are examined using instantaneous differential pressure measurements and flow visualization by streakline photography. Cavity dominated flow features are observed in short cavities while the entry flow dominates in longer cavities. The pressure fluctuations generated by elastic flow instabilities are as much as 30% of the nominal value and the dynamics of the how become strongly non-linear and very complicated especially at high flow rates. (C) 2001 Elsevier Science B.V. All rights reserved.