Quaternary AlInGaN materials represent a novel class of semiconductor compounds, which can be used in UV optoelectronics demonstrating a number of advantages. After brief evaluation of peculiarities of structure and growth specifics of AIInGaN layers and multilayered structures, we review the results on investigation and analysis of the radiative recombination dynamics of MOCVD-grown AlInGaN-based layers and multiple quantum wells (MQWs) in a wide temperature range and under different excitation conditions. The discussion is focused on carrier localization and the influence of indium on mobility and recombination of photoexcited carriers. Recent results on study of indium spatial distribution and simulation of exciton hopping in AlInGaN are summarized. Additional influence of built-in electrostatic fields due to spontaneous and piezoelectric effects in MQWs on the photoluminescence dynamics is also addressed. Different mechanisms of optical transitions in AIInGaN systems are analyzed. The prospects for practical application of these quaternary materials for UV emitters are discussed.