Microalgae when subjected to stressful environmental conditions they release gel- like exudates known as exo-Polysacchrides. These have been able to find several applications in the fields of cosmetics for skin-rejuvenation ability and for incorporation into the skin care cosmetic formulations. The aim of this study was to study the proliferative and wound healing ability of the exo-polysaccharide extract using the MTT proliferative assay along with the in-vitro scratch assay on the swiss embryonic 3T3 fibroblast cell line. This extract was added in 5 different concentrations from 50-500 ug/ml. The vehicle control used was Citrate buffer and the positive control was Standard PBSA. Physico-chemical properties exhibited by the microalgae of forming hydrogels which could be used in the cosmetic formulations as mositursing agents, stabilising agents, viscosity enhancing agents and emulsification agent. The syntetic emulsifier in the O/W emulsion was replaced by in the present research. The exo-polysaccharide extract was also tested for its moisturizing efficacy studies using the scalar moisture checker instrument. From the proliferation assay results, it can be concluded that the extract on the addition into the 96-well plate was found to stimulate the proliferation and migration of the cells at higher concentrations up to 400ug/ml of the extract without any cytotoxicity to the cells after 24 hours of exposure with the added exo-polysaccharide extract of P.limnetica. From the findings it can be concluded that the cyanobacterial P.limnetica polysaccharide extract will be beneficial to treat various chronic wounds and other skin related wounds and it can be also utilised in the skin-rejuvenating cosmetic formulations for anti-aging. The results noted from the moisturizing ability studies prove that after 6 hours of the exposure time the moisturizing ability increased to 24.64±0.779 as compared to control reading of 22.56±0.669. The increase was found to be nearly to 6- 8% on the addition of the 0.1% of the Pseudanabaena limnetica exo-polysaccharide extract in the cosmetic formulations.