Cavitation in reciprocating positive displacement pumps is still an insufficiently understood problem. For a better understanding of the effects of cavitation in reciprocating positive displacement pumps, high-speed camera measurements were done under real operating conditions. In this work, emphasis is put on the recording of cavitation phenomena for further investigations. Exemplarily, the occurring cavitation phenomena for different valve designs are described on the basis of high-speed sequences for selected cavitation conditions and the results are discussed.