A detailed surface evaluation was performed for the components of two multistage centrifugal pumps for water injection in a Venezuelan oil production field. Several non-destructive methods were employed: visual inspection die penetrant and replica extraction followed by micro-morphological and chemical analysis by scanning electron microscopy (SEM) and energy dispersive X ray (EDX) spectroscopy. The flow-induced degradation mechanisms varied depending on the pump component and their ranking according to damage intensity from high to low was: i) severe erosion-corrosion in the balance bush system; ii) severe erosion-corrosion in the middle bush; iii) wear of variable intensity of the active face of wear-rings; iv) mild wear of the babbitt coated sliding bearings; v) axially oriented erosion of the contact surface between wear-ring and spindle; vi) high viscosity deposits of oil in the outlet stages; vii) spindle oxidation; viii) pitting inside impeller periphery slots; ix) deposition of crystallized salts. The criticality ranking fairly agreed with the performance history of the pumps.