The role of the microstructure on the hot deformation behavior of sintered Cu-28Zn prealloyed powder compacts was investigated by a series of isothermal hot compression tests in the temperature range of 550- 850°C at strain rates of 0.001, 0.01, 0.1 and 0.5 s-1, assuming the Hyperbolic Sine functional behavior to analyze the deformation behavior of the alloy. The results indicate that dynamic recrystallization has occurred in large scale. It was found that increasing the temperature resulted in larger mean grain size. The amount and the size of dynamically recrystallized grains increased as the Zener–Hollomon parameter decreased. The effect of strain rate and temperature on dynamically recrystallized grain refinement was investigated. Microstructure is in compliance with the results through the Zener-Hollomon relation and has satisfied hot deformation stress- strain curves. This study may provide a new understanding on the relationship between mechanical properties, microstructure and processing of α brass alloy.