Processes of formation of a dusty ionospheric plasma and physical processes in the plasma are discussed. The emphasis is given to the role of dust particles of meteoritic origin as well as the particles formed as a result of water vapor condensation in the polar summer mesosphere. A self-consistent model of the dusty ionosphere which allows for grain growth, sedimentation, and charging is developed. This model is used to explain the main ionization properties of the polar summer mesosphere. Wave properties of the dusty ionosphere are also discussed. In particular, the excitation of low-frequency dust acoustic perturbations and their manifestations are considered. Ground-based in situ measurements are discussed which can be helpful from the point of view of the evidence of the dust acoustic mode in the ionosphere. New vistas in investigation of physical processes in ionospheric dusty plasmas are stated.