In this study, five microalgal strains were isolated from Bahía de La Paz, Baja California Sur, Mexico and identified as Grammatophora sp., Navicula sp., Rhabdonema sp., Schizochytrium sp., and Nitzschia sp., and their evaluation as potential food for Artemia franciscana. The isolated strains were cultured outdoors and harvested after four days. Chaetoceros muelleri was cultured under laboratory conditions and used as control. The protein, lipid, and carbohydrate composition and the fatty acid profiles of the strains were determined by gas chromatography. To assess the effect of microalgal strains on A. franciscana, decapsulated cysts were cultured at outdoor conditions in 15 L containers. The experiment was conducted for twelve days. Samples from the five different feeding treatments were taken at the beginning and end of the experiment to assess number, size, and weight of Artemia larvae. Treatment with Rhabdonema sp. showed larvae with a lower percentage of polyunsaturated fatty acids (PUFAs) while Grammatophora sp. showed those with the greatest PUFA proportion, even more than those fed Chaetoceros muelleri (control). Larvae consuming Schizochytrium sp. had no docosahexanoic (DHA) nor eicosapentaenoic (EPA) fatty acid content. Growth and survival of A. franciscana did not show significant differences among feed treatments, except when it was fed Nitzschia sp., showing lower survival and dry weight. Treatment based on Schizochytrium sp. and Rhabdonema sp. had a greater A. franciscana size but reduced dry weight; additional tests including two or more algal species for every treatment should be carried out to determine the best yieldIn (our) this study, five strains of microalgae were isolated from Bahía de La Paz, Baja California Sur, Mexico and further identified as Grammatophora sp., Navicula sp., Rhabdonema sp., Schizochytrium sp., and Nitzchia sp. by standard taxonomic studies. The strains were cultured outdoor and (hatched) harvest after four days. The protein, lipid, and carbohydrate composition and the fatty acid profiles of the strains were determined by gas chromatography. To assess the effect of microalgae strains in Artemia franciscana, were decapsulated the cysts (A. franciscana) and then cultured at outdoor conditions at one nauplius mL-1 and the microalgal density was maintained at 70 000 cells mL-1. The experiment was conducted in 15-L tanks for twelve days.  Samples were taken at the beginning and end of the experiment to assess the number, size, and weight of Artemia larvae. Rhabdonema sp. showed a lower percentage of polyunsaturated fatty acids (PUFAs), while Grammatophora sp. had the greatest proportion of PUFAs, even more than Chaetoceros muelleri (control). The microalga Schizochytrium sp. did not show either Docosahexanoic (DHA) or Eicosapentaenoic (EPA) fatty acids. Growth and survival of A. franciscana did not show significant differences, except when Artemia was fed with Nitzchia sp., showing lower survival and dry weight. Treatments based on Schizochytrium sp. and Rhabdonema sp. had a greater size. It is advisable to use the present strains for culturing A. franciscana.