Microalgae are excellent reservoirs of adiverse range of nutraceuticals.The presence of secondary metabolites, pigments, vitamins makes microalgae unique reservoir of nutraceuticals. Many strains of microalgae are known to produce intracellular and extracellular metabolites with diverse biological activities such as antibacterial and antifungal;in addition, to it, they are also rich in adiverse range of antioxidants, vitamins and pigments. There is a drastic increase in cases of antibiotic resistance and exploring the antimicrobial efficacy of microalgae can aid in resolving the problem. In this study we have investigated the activity of Microalgae Anabaena variabilis, Synechococcus elongates andSpirulinaplatensisagainst the human pathogenic bacteria namely Enterococcus sp, Esherichiacoli, Pseudomonas sp, Klebsiella sp.Experimental results show that microalgal extracts are capable of inhibiting the growth of pathogenic bacterial strains. Methanol (60%) extract of Anabaena variabilisgave 30mm zone of inhibition against E.coliand methanol extract of Synechococcus elongates gave the highest antimicrobial activity against Enterococcus (32mm inhibition zone) and Pseudomonas sp. (26mm inhibition zone). S.platensis shows highest antimicrobial activity against E.coliwith Methanol (100%). As per the formation of zones, ethanol (100%) extract, butanol, water, acetone and methanol (100%) extract gave a high visibility of zone of inhibition.Exploring the nutraceutical efficacy of microalgae can efficiently address theplethora of drug related issues and, in addition, serve as asource of nutrients.