There is a large body of evidence suggesting that words learnt early in life are recognised and produced faster than words learnt later in life, even when other variables are controlled. This is known as the Age of Acquisition (AoA) effect. However, there is an aspect of AoA that requires research of a greater depth, namely the method of obtaining the AoA measures. In the majority of studies, adult participants were asked to estimate the age at which they learnt a given word. Morrison, Chappell, and Ellis (1997) proposed a new method for obtaining objective-AoA data. They asked children to name some objects, and the age at which a given word appeared with 75% or more frequency was considered the AoA of that word. Although this method is more valid than adult ratings, it has only rarely been used. The main aim of this work is to provide objective-AoA norms in Spanish for a set of 175 object names following the procedures used by Morrison et al. The relationships among objective-AoA, estimated-AoA, and other psycholinguistic variables (name-agreement, familiarity, visual complexity, word length, etc.) obtained from a previous study are also analysed. Finally, the similarity of objective- and estimated-AoA measures was examined using data from several languages. A cluster analysis and a multidimensional-scaling analysis revealed that the estimated-AoA measures in a language correlated more with the estimated-AoA measures of the other languages than with the objective measures in the same language. The results suggest that it would be desirable to always use objective-AoA norms because they are less skewed by familiarity.