β-Glucans, homopolymers of glucose, are widespread in many microorganisms, mushrooms and plants. They have attracted attention because of their bioactive and medicinal functions. One important source of β-glucans is the cell wall of yeasts, especially that of baker's yeast Saccharomyces cerevisiae. Several processes for the isolation of β-glucans, using alkali, acid or a combination of both, result in degradation of the polymeric chains. In this paper, we have an enzymatic process for the isolation of glucans from yeast cell walls. As a result, β-glucans were obtained in a yield of 18.0% of the original ratio in the yeast cell walls. Therefore, this isolation process gave a better yield and higher β-glucan content than did traditional isolation methods. Furthermore, results showed that each extraction step of β-glucan had a significant effects on its chemical properties.