A polyherbal suspension was formulated from the extracts of roots of Cyperus rotundus (CRR) and leaves of Azadirachta indica (AIL) and Bryophyllum pinnatum (BPL). The suspension had very good redispersibility and was very stable without agglomeration, caking or microbial growth. Study of diuretic activity was done on individual plant extract as well as formulation. There was a significant increase in the volume of urine and electrolytes Na+, K+, Cl- which was similar to the standard drug furosemide. The formulation had much better activity as compared to the individual drug extracts which may be due to the synergistic effect of the herbs used. There was no significant change in pH. The loss in electrolytes Na+, K+, Cl- may lead to a reduction in supersaturation of calcium in urine thereby preventing the formation of kidney stone. The PHF have good diuretic activity and can be used to reduce hypertension, kidney problems and urolithiasis.