The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computerassessed test battery widely use in different populations. The internal consistency and one-year stability of CANTAB tests were examined in school-aged children. Two hundred-thirty children (57% girls) from 5 schools in the Jyväskylä school district in Finland participated in the study in spring 2011. The children completed the following CANTAB tests: a) visual memory (Pattern Recognition Memory [PRM] and Spatial Recognition Memory [SRM]), b) executive function (Spatial Span [SSP], Stockings of Cambridge [SOC], and Intra-Extra Dimensional Set Shift [IED]), and c) attention (Reaction Time [RTI] and Rapid Visual Information Processing [RVP]). Seventy-four children participated in the follow-up measurements (64% girls) in spring 2012. Cronbach’s alpha reliability coefficient was used to estimate the internal consistency of the nonhampering test, and structural equation models were applied to examine the stability of these tests. The reliability and the stability could not be determined for IED or SSP because of the nature of these tests. The internal consistency was acceptable only in the RTI task. The one-year stability was moderate-to-good for the PRM, RTI, and RVP. The SSP and IED showed a moderate correlation between the two measurement points. The SRM and the SOC tasks were not reliable or stable measures in this study population. For research purposes, we recommend using structural equation modeling to improve reliability. The results suggest that the reliability and the stability of computer-based test batteries should be confirmed in the target population before using them for clinical or research purposes.