Current biofuel production utilizing microalgal biomas is not cost effective. Hence increasing research interest is to find out new microalgal candidate to make microalgal products and by-products economically viable. Several promising microalgal species have drawn scientific interest as they offer commercial sources of high-value by-products (chemicals) such as β-carotene, astaxanthin, docosahexaenoic acid, eicosapentaenoic acid, bioactive and functional pigments, natural dyes, polysaccharides, antioxidants and algal extracts. These species play a significant role in cosmaceuticals, nutraceuticals, pharmaceuticals, fodder, aquaculture, bioremediation and human foods. For making algal biomass production economically viable, high value by-product extracting is paramount. This article emphasises on some important microalgal species that offer such high value by-products for commercial applications.