Day-care centers and pre-schools highly benefit from precise and reliable screening measures. Ages and Stages Questionnaire was adapted to Brazilian Portuguese in 2010 (Filgueiras et al., 2013) and renamed ASQ-BR. Regardless of its good results, modifications in a few items were required to improve the instrument s measure. The objective of the present study is to modify such ASQ-BR s items and verify if the changes increase the reliability of the test. This study researched 67,522 children from 972 public day-care centers and pre-schools of Rio de Janeiro, Brazil. The data was collected in November and December, 2011. The changes in the items were made considering Cronbach s alpha and item-to-total correlations in ASQ-BR. Reliability, dimensionality and item to total correlations were calculated. Regarding dimensionality, 86.2 per cent of the scales in ASQ-BR-2011 were unidimensional. Internal consistency showed improvement from 2010 to 2011, 53.8 per cent of the scales increased the alpha statistics against 41.2 per cent that decreased – 5.0 per cent remained the same. Finally, 65.2 per cent of the modified items showed improvement based on item-to-total correlations. Though the objective of the present study was partially achieved, a few scales presented results below the established criteria. In contrast, the instrument s measure improved in several aspects from 2010 to 2011, especially in the Personal/social domain.