With the aim to identify new microalgae species that could be used as live food in aquaculture, we determined the growth rate, proximal composition, fatty acid profile and toxicity of 21 microalgae (Cyanophyceae (3), Chlorodendrophyceae (1), Xanthophyceae (1) and Bacillariophyceae (16)), isolated from Baja California (NW México) coastal waters. Cyanophytes Komvophoron sp. had the highest growth rates (μ = 2.98 divisions day-1) and Aphanocapsa marina had the highest cell density (11.92 x 106 cell mL-1). Xanthophyceae Heterococcus sp. had the highest cell size (193.12 µm) with lower growth rates (μ = 0.67 divisions day-1). The lipid, protein and carbohydrate percentage of the isolated strain were different between growth phases and strains. The diatom Amphora sp. (strain 3) had the highest lipid percentage (57.7%) during exponential growth phase. The diatom Cymbella sp. (strain 2) had the higher proteins percentages (39.5%) and highest (47.5%) carbohydrate on stationary growth phase. Fatty acid content differed according to taxonomic group. Diatoms contained the highest percentages of polyunsaturated fatty acids (n-3 and n-6 PUFAs), ranging from 23.8% to 60.7%, and eicosapentaenoic acid (EPA) was the most abundant. None of the isolated microalgae strains were toxic to Artemia franciscana nauplii. We conclude that based on their growth rate, proximal composition, fatty acid profile, and lack of toxicity of the isolated microalgae strains, have the potential to be use for aquaculture activity alone or as part of a mixed diet. The growth rate, fatty acid profile and toxicity of 21 microalgae strains (Cyanophyceae (3), Chlorodendrophyceae (1), Xanthophyceae (1) and Bacillariophyceae (16)), isolated from coastal waters of Baja California (NW México), were determined. Cyanophytes Komvophoron sp. had the highest growth rates (μ = 2.98 divisions day-1) and Aphanocapsa marina had the highest cell concentration (11.92x106 cell mL-1). xanthophyte Heterococcus sp. had the largest cell size (193.12 µm) with lower growth rates (μ = 0.67 divisions day-1). Fatty acid content differed according to taxonomic group. Diatoms contained the highest percentages of polyunsaturated fatty acids (n-3 and n-6 PUFAs), ranging from 23.4 to 60.7%, and eicosapentaenoic acid (EPA) was the most abundant. None of the residual media from the isolated microalgae strains were toxic to Artemia franciscana nauplii. We conclude that based on their growth rate, fatty acid profile, and lack of toxicity, all the isolated microalgae strains have the potential to be used alone or as part of a mixed diet for the culture of marine organisms.