Purpose <p>The study aimed to evaluate the growth capacity and nutrient removal efficiency of <i>Chlorella vulgaris</i> in fish wastewater (FWW) and Bold's Basal (BB) medium as a control. The research question was whether <i>C. vulgaris</i> could effectively grow and remove nutrients in FWW.</p> Methods <p>The experiment was conducted under controlled conditions in a climatic chamber. <i>C. vulgaris</i> was grown in FWW and BB medium. Cell counting, optical density, and dry weight were measured daily. The nutrient removal efficiency was determined by analysing total nitrogen (TN) and phosphate (P-PO₄³⁻) concentrations.</p> Results <p>The growth of <i>C. vulgaris</i> in both media was gradual, with an exponential phase from day 2 to 10 in BB medium and from day 4 to 10 in FWW. TN removal reached 89.09% in BB and 98.11% in FWW, while P-PO₄³⁻ removal was 34.06% in BB and 98.45% in FWW.</p> Conclusion <p><i>C. vulgaris</i> demonstrated efficient growth and nutrient removal in fish wastewater, making it a promising candidate for wastewater treatment and biomass production in the Cuban agro-industrial sector.</p> Graphical Abstract <p></p>