Drought is one of the most common forms of abiotic stress and has direct impact on the viability and productivity of plants. From the point of view of physical chemistry, drought is characterized by a decrease of the water potential of the environment and effects on many biochemical processes in the plant cell, which causes the development of oxidative stress. Events triggered by water deficiency lead to disruption of the electron-transport chains of mitochondria and chloroplasts, which leads to excessive generation of reactive oxygen species and, as a consequence, to the development of oxidative stress. Oxidative stress, in turn, causes modifications at the molecular and physiological levels in plants. That is why many researchers use a wide range of physiological parameters for characterization of the development of the drought stress response in plants. In this review, we tried to summarize the available recent experimental data from many recent studies, describing the main mechanisms of stress response in plants. In particular, we paid attention to those physiological parameters, whose changes occur in most plant species.