An assessment of inlet swirling flow, cavitation behaviour and their effect on flow at the inlet of a pump is essential to understand the phenomenon of reverse flow in radial flow pumps. With this aim, a set of five tufts arranged in a radial direction inside the suction pipe of a radial flow pump has been used. The experimental studies belong to two groups: one under cavitation-free conditions, and the other at different static suction lifts. A hysteresis is noted in the appearance and disappearance of swirling flow. The geometry of swirling flow is assessed qualitatively by visual studies. The swirling flow spreads towards inner radius slowly at lower static suction lifts and quickly at higher static suction lifts as the discharge decreases. High speed photographic recordings made at different discharges at the low flow region reveal that cavitation zones in the vane channels move from one channel to the other through the suction pipe.