This presentation relates to the cavitation studies on centrifugal pumps wherein loss of performance and noise and vibration effects were evaluated experimentally together with visual observations. The details of the five experimental pumps (designated as IMP0, IMP1, IMP2, IMP3 and IMP4) employed for the investigation are presented together with typical results obtained. The 5 pumps were obtained by changing the impeller alone in the same casing. IMP0 was designed for a different set of data compared to the other impellers. IMP1, IMP2 and IMP3 have the same dimensions but have different number of vanes. IMP4, designed for the same data as that of IMP1, IMP2 and IMP3, has a different geometry. First, the cavitation-free performance of the five pumps were determined at various speeds. The points of optimum efficiency were then found out.