Sulfated polysaccharides (fucoidan) were recovered from brown seaweed Fucus vesiculosus by microwave-assisted extraction (MAE). Different conditions of pressure (30–120psi), extraction time (1–31min), and alga/water ratio (1/25 to 5/25gml⁻¹) were evaluated during this process aiming to establish a condition to maximize the extraction results. The alga degradation (%), total sugar yield (%), and SO₃ content (%) were also determined to each experimental condition. All the studied variables presented significant (p<0.05) influence on fucoidan yield. MAE at 120psi, 1min, using 1g alga/25ml water was the best condition for the fucoidan recovery. l-Fucose was the main constituent of this polysaccharide, which also contained xylose and galactose. MAE under optimum reaction conditions was an effective method to recover fucoidan from F. vesiculosus. This method required short extraction times, and non corrosive solvents, resulting in reduced costs and being an environmentally friend technique.