Abstract: The present investigation was aimed at studying the effect of culture filtrates of cyanobacteria (blue green algae) namely Anabaena ambigua Rao and Oscillatoria foreaui Fremi in different soil conditions on the growth of Withania somnifera Dunal in terms of biomass and biochemical characteristics along with active ingredients of the roots. Experiments conducted in field by replenishing the plant rhizosphere as foliar spray with increasing quantities of culture filtrates enhanced the growth of the plant more precisely in sandy loam soil when compared to red soil. The yield potentials of the roots also increased with the culture filtrate of O. foreaui along with the other parameters studied, attributing to the availability of the nutrients from the cyanobacterial culture filtrates.