Throttle elements in hydraulic systems are susceptible to cavitation. High fluid velocities within constricted passages can lead to the formation of vapor bubbles due to localized pressure drops. Upon entering regions of higher pressure, these bubbles collapse violently, inducing a range of detrimental effects, such as shockwaves that cause material erosion of the channel, intense acoustic emissions, and the adiabatic compression of the vapor within the collapsing bubbles can result in significant localized temperature increases. Under certain conditions, a phenomenon known as hydrodynamic luminescence also appears. There are many theories of how this complex effect occurs, but still no certainty among scientists about one of them. In this study, an attempt was made to visually detect the appearance of luminescence during hydrodynamic cavitation in a throttling device as a function of inlet pressure. The investigation also aimed to assess the occurrence of electrical charges in the region where luminescence was observed and to determine the influence of a magnetic field on luminescence intensity. Experiments were conducted using a cavitation device constructed from organic glass, with hydraulic oil of the “H-L” type as the working fluid. The results revealed the presence of electrical charges concurrent with luminescence and demonstrated the impact of a magnetic field on its intensity. These findings may support the applicability of electrical discharge theory in studying the luminescence observed during hydrodynamic cavitation.