This study aimed to evaluate the effect of different ultrasound (US) powers on physical properties of a prebiotic soursop-flavored whey beverage and compare to conventional method of rapid pasteurization (RP). The whey beverage was manufactured with whole pasteurized and homogenized milk (30 g 100 g⁻¹), whey powder (6 g 100 g⁻¹), soursop pulp (15 g 100 g⁻¹), sugar (8 g 100 g⁻¹) and inulin HP (6 g 100 g⁻¹) of DP (degree of polymerization) ≥23. The US was applied in 25-cm³ samples, for 3 min at different powers (200, 400 and 600 W), one sample was submitted to RP (72–75°C for 15–20 s), and one was unprocessed (US 0 W). US effects on whey beverage properties was evaluated, immediately after its manufacturing, using particle size distribution (PSD), color (L* a* b* measurements) and rheological properties (flow curves). US technology presented color difference from US 0 (ΔE*) similar to RP (2.1) at 200 W (1.9) (P = 0.34), but significantly higher at 400 W (2.6) and 600 W (2.4) (P < 0.01). All samples presented a pseudo plastic behavior, however, the US increased the flow behavior index (n) and reduced the consistency index (k) (P < 0.01), unlike RP sample which remained unaltered for n (P = 0.73) and for k (P = 0.88). Furthermore, no influence of US power were observed for rheological parameters, including apparent viscosity, which was not influenced by US or RP (P > 0.05). The greater D32 value reduction, compared to US 0 W, was 26.6% at US 200 W (P < 0.02) and for D43 values were 58.1% and 44.2% at US 600 W and RP (P < 0.01), respectively. The PSD value suggest a considerable change in large particles for US 600 W and RP and size reduction of smaller particles for US 200 W. Based at the conditions used in this study, US technology presented effects on the color parameters of soursop-flavored whey beverage; however no effect was observed the rheology behavior.