Colloidal quantum dots of perovskites having the chemical composition CsPbBr3 have been synthesized. For these particles, the average size of an ensemble of particles and sample polydispersity have been determined by steady-state spectrofluorometry. Conducting layers were made from the obtained particles, and the electrophysical characteristics of these layers were measured. The hole nature of the conductivity wasestablished, and the layer conductivity (0.04 S/m), mobility (0.8 cm2/(V s)), and number concentration of free charge carriers (3.01 × 1021 m−3) were measured. In accordance with published data, the measured mobility value is higher by one to two orders of magnitude than published typical values. It is shown that high polydispersity has a weak effect on the electrophysical and transport characteristics in the resulting layers.