Agile beam phased array radar (PAR) with polarization diversity is the subject of this paper. Because polarization is controlled at the element level and from pulse to pulse, the polarimetric PAR offers unprecedented versatility. Thus, a resolution volume can be illuminated with arbitrarily polarized waves in rapid succession while choosing the polarization basis as function of direction for optimum identification of scatterers. That way, it is possible to use a polarization basis, which provides the largest contrast for some hydrometeor types in regions were these are expected to be present. For example, circular depolarization ratio is an excellent indicator of aligned ice crystals and is independent of their mean orientation. Therefore, a circularly polarized wave can be sent in the direction where crystals are expected and both co and cross polar components can be received; this could be followed by transmitting a linearly polarized wave. Nonetheless, the design of the transmitted sequence has to accommodate measurements of standard spectral moments as well as to provide some degree of protection against ambiguities in velocity and range. These possibilities and demands are examined. Further, consideration is given to some simpler (less expensive) variants of the agile beam polarimetric PAR. Finally, the pros and cons of the few possibilities are brought out.