High isostatic pressure (HIP) is an emerging non-thermal food preservation technology that can contribute to maintain the characteristics of fruit pulp similar to fresh fruit. The knowledge of rheological properties is useful for the quality aspects and process/equipment design. Tropical fruits have gained market due to its unique flavours and bioactive compounds, and açaí is one of the most important brazilian fruit in this scenario. The conventional thermal process of açaí pulp can alter major quality aspects such as colour, flavours and on bioactive compounds contents, and HIP technology is a potential alternative. This study evaluated the change in the rheological parameters of açaí pulp processed by HIP. The samples were processed at 600MPa for 5min at 25°C and 65°C. A sample thermally processed (TP) at 85°C for 1min was used for comparison purposes. The samples were analysed on a stress-controlled rheometer in which thixotropy and flow behaviour were verified. Figoni-Shoemaker model was used to describe the thixotropy and the Hershel-Buckley model to describe the flow behaviour. All samples presented a shear-thinning with yield stress behaviour. The TP sample presented a slightly higher thixotropy (initial and equilibrium stresses) and consistency, noted by the slightly increase in the yield stress and consistency index, and the slightly decrease in the behaviour index. For HIP samples, the higher the pressure higher was the increase in thixotropy and consistency. The sample at 25°C presented nearly the double of consistency of the control, and the sample at 65°C presented approximately four times the increment in consistency. The increase in the rheological parameters due to high pressure can be an improvement to consumer perception, since it is desirable a high consistency in this product. In addition, the knowledge can be used on industrial and product design in the future by the food industries in general.