A microbial sensor based on a carbon dioxide electrode coupled with immobilized Saccharomyces cerevisiae (baker's yeast) has been used for the determination of sucrose in dairy products. The sensor was used as the detector in a flow injection analysis system. Calibration curves for sucrose were established from 1 to 100 g/l. Determinations for several dairy products containing added sucrose gave good agreement with the concentrations given by manufacturers. Typically, the se of the method was shown to be <5% of the calculated mean.