Cell growth and polysaccharide production by a local strain of Ganoderma lucidum was studied using thin stillage with additive carbon source. By adjusting the pH 5, 60% thin stillage was used successfully to grow the mycelia of G. lucidum with the highest cell concentration of 7.8 g/L and polysaccharide production of 7.50 g/L. Using various sugar additives, molasses addition produced the highest mycelia growth rate and cell concentration while cell concentration increased significantly to 12.7 g/L. In contrast, glucose addition led to increase overall polysaccharides production up to 3.69 g/L which is three times to that without addition. Polysaccharides in the range of molecular weight from 10,000 to 200,000Da were also found at almost three times production with thin stillage only. The intracellular polysaccharides and extracellular polysaccharides of G. lucidum showed a similar molecular weight distribution, but a slightly higher molecular weight of intracellular polysaccharides was recorded. (C) 2004 Elsevier Ltd. All rights reserved.