Candida utilis was grown on pineapple cannery effluent as the sole carbon and energy source. These effluents are rich in microbially utilizable nutrients. The principal sugars in the effluent were glucose, fructose and sucrose, and when supplemented with diammonium hydrogen phosphate to prevent nitrogen limitation they supported good growth. The maximum specific growth rate (m=0.46h–1) and cell yield coefficient (Yc/s=0.30) were obtained with 23.2 g carbohydrate/l in the growth medium. The values of m and Yc/s varied with carbohydrate concentration: higher values of m and Yc/s were obtained with lower concentrations of carbohydrate, suggesting that a chemostat would be more suitable for single cell protein production. Freeze-dried yeast contained 55.3, 51.2, 1.45, 6.4 and 27.4% of crude protein, true protein, DNA, RNA and carbohydrate respectively. The yeast had a balanced amino acid profile, except for sulphur-containing amino acids. A 90–95% reduction in the chemical oxygen demand of the effluent was achieved during this process which suggests that yeast may be effectively used to treat this waste.