Suboptimal effort is a threat to the validity of neuropsychological evaluations. Numerous papers have been devoted to this subject and a large number of measures have been developed in an attempt to detect suboptimal effort. To date, however, the clinical literature has focused almost exclusively on identifying suboptimal effort in adults, whereas suboptimal effort among children has not been addressed thoroughly in the clinical neuropsychological literature. The present study investigated whether or not already established effort measures could be used with children. The Test of Memory Malingering (TOMM) and the Rey-15-item test were administered to 128 children in two sites, the USA and Cyprus. The results indicated that the TOMM has the potential to be used as a measure for identifying children who do not put forth maximal effort during neuropsychological evaluations. In contrast, the Rey-15-item test does not appear to be a promising measure of effort for use with children, especially younger children.