Description: Since its foundation, the European Social Survey (ESS) has evaluated the quality of their measurement instruments. Over the rounds the ESS conducted Multitrait-Multimethod (MTMM) experiments in order to estimate the quality of its survey questions. In this way, since the first round, question quality was estimated for more than 250 items, in more than 20 different countries and languages. We use information for 16 experiments conducted in the last five rounds (Round 4 to 8) to analyse the quality of survey questions in Spain in comparative perspective. Moreover, we present an example of the importance of correcting for measurement errors in cross-national research. Overall, we find that the average measurement quality of Spain is rather similar than the average of the ESS, with a few exceptions. However, for 7 of the 16 experiments analyzed, the best performing method in Spain is not the same as for the majority of the countries. Moreover, our example demonstrates that substantive conclusions when conducting cross-national research can be wrong if not corrected for measurement errors.