This work discusses the presence of gas-phase turbulence in the flow taking place in the circulating fluidized-bed riser. The experimental basis consists of measurements of pressure fluctuations and gas mixing by tracer-gas injection. Several observations, such as a power-law fall-off in the power spectrum of the pressure fluctuations, point at the existence of turbulent structures in the gas flow. The dense bottom bed is of importance because of high local gas velocities through the bubbles passing the bed. The bubbles and consequently the perturbations generated, are unevenly distributed in space and time. Experimental data of gas diffusivity are compared to published data on diffusivity in single-phase turbulent flows.