ABSTRACT Between the ages of 3 and 5, children develop greater control over attention to visual dimensions. Children develop the ability to flexibly shift between visual dimensions and to selectively process specific dimensions of an object. Previous proposals have suggested that selective and flexible attention is developmentally related to one another. However, the relation between flexibility and selectivity has not been systematically probed at the behavioral and neural levels. We administered a selective attention task (triad classification) along with a flexible attention task (dimensional change card sort) with 3.5 -and 4.5-year-olds while functional near-infrared spectroscopy data were recorded. Results showed that children with high flexible attention skills engaged the bilateral frontal cortex which replicates previous studies using this task. Moreover, children with high levels of selective attention engaged the right frontal cortex. Together, these results indicate that development in the right frontal cortex is important for both flexible and selective dimensional attention.