The paper discusses the problem of pressure pulsation in hydraulic systems. The most important causes of pressure disturbances were discussed, such as: instability of the pump performance, variability of the system load and transient states related to the control of the system. The next part presents the threats caused by pressure fluctuations. On the one hand, the effects of the occurrence of a water hammer are presented, as a temporary exceeding of the maximum operating pressure of the system. On the other hand, the problem of fatigue strength of the system was presented, which was illustrated on the example of tests and calculations of hydraulic cylinders and hydraulic hoses. In the last part, the author indicated further directions of literature, simulation and experimental research.