Effects of picobubbles on froth flotation of coarse phosphate particles (-1180 mu m + 425 mu m) have been investigated with a specially designed flotation column. Cavitation generated picobubbles are characterized by inherently high probability of collision, high probability of attachment, and low probability of detachment during froth flotation due to their tiny size and high surface activity. Test results obtained with a 5 cm in diameter laboratory scale flotation column indicate that picobubbles are effective in enhancing the flotation of coarse phosphate particles, and increasing the flotation recovery by 10 to 23 absolute percentage points under various conditions. The required collector dosage and frother dosage for a given flotation performance were reduced by one-half to two-thirds.