In maize leaves, the intercellular distribution of photorespiratory enzymes was investigated with bundle sheath strands and mesophyll protoplasts isolated enzymically and obtained with a high degree of purity. Phosphoglycolate phosphatase was found to be exclusively located in bundle sheath which also contained about 90% of the whole leaf activities of catalase, glycolate oxidase, and hydroxypyruvate reductase. The spatial compartmentation of the photorespiratory process in corn leaves is discussed on the basis of the data reported in this study, together with those of other reports.