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 are developmentally related to one another (e.g., Hanania & Smith, 2010). However, the relationship 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 bilateral frontal cortex which replicates previous studies using this task. Moreover, children with high levels of selective attention engaged right frontal cortex. Together, these results indicate that development in right frontal cortex is important for both flexible and selective dimensional attention.