The Bayley Scales of Infant Development 2nd edition (BSID-II) is used worldwide as a test for assessing development in infants with congenital heart disease (CHD); however, a Japanese version of these tests is not available. To introduce BSID-II in Japan, it was first used for 1-year-old Japanese infants with and without CHD (controls). The BSID-II scores of the control group were lower than American standards. In addition, the scores of the infants with CHD were lower than those of the controls, particularly the scores for motor development. Tsumori's Mental Development Test scores for the two groups were comparable; however, a diverse correlation was observed between BSID-II and Tsumori's Mental Development Test. No problems were encountered during the translation and use of BSID-II. These results suggest that BSID-II is useful for the assessment of development in Japanese infants.