This study examines public opinion about the National Assessment Program--Literacy and Numeracy (NAPLAN) in Australia, based on an online survey conducted with a sample of New South Wales (NSW) residents (n = 2,017). Our study participants did recognize the benefits of NAPLAN despite their opinion generally trending toward negative viewpoints of the testing program. The views about the positive aspects of NAPLAN varied across socio-demographic groups, but there were more similar views concerning the negative views of NAPLAN. As predicted by the social-cultural and institutional performance models, those living in metropolitan areas and those from high SES groups tended to possess stronger positive views. Political party preference was a strong predictor of the perceptions about NAPLAN. Overall, this study offers possible explanations for the underlying mechanisms explaining sub-group differences in attitudes toward large-scale standardized national testing.