To study the phytoconstituents present in some selected seaweeds collected from the Rasthakaud coastal waters, southeast coast of Kanyakumari district, Tamilnadu, India. Phytochemical screening of the seaweed extracts were carried out using standard methods. The present study screened the phytochemical properties of eleven seaweeds with fourty four extracts and showed varied degree of phyto-constituents present. The presence or absence of phytoconstituents depends upon the solvent medium used for extraction and the physiological property of the seaweeds. From the results of the present study, it can be concluded that the seaweeds may be used as broadspectrum antimicrobial and bioactive agent after extensive investigation.