Fish processing wastewater (FPWW) has the potential for providing inorganic and organic nutrients, which can be chemically processed and produced as a medium for the production of microalgae. Here the effects of FPWW (1, 3, 5, and 7 mL/L) and Walne medium (as a control) on the growth, biomass, and biochemical content of Dunaliella sp. were evaluated. An increase in FPWW concentration enhanced the growth, biomass production, and pigment and protein content of Dunaliella sp. There was no significant difference in the growth, biomass, pigment, protein, and lipid content between the FPWW concentration of 7 mL/L and Walne medium (control) (P > 0.05). Interestingly, significant 4.4- and 4.1-fold increases in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs), respectively, were observed for Dunaliella sp. cultured in FPWW at 7 mL/L vs. Walne medium. The authors conclude that treated FPWW can potentially be used as a medium for the growth of microalgae.