A quick iodine staining test was utilized to screen leaves for the capacity to accumulate starch from exogenously supplied glucose. Five maize mutants which had reduced capacities for starch accumulation were isolated from chlorophyll-deficient stocks. Quantitative starch determinations confirmed the visual test results. The mutants, l 4, l7, l3, l4920, and w 11, accumulated 3, 4, 18, 29, and 35% of the starch of their respective normal sibs. These mutants are promising material for studies of enzymes responsible for starch biosynthesis and may prove useful for investigations of gene-plastid-enzyme relationships.