The relationships between national personality traits and intelligence from 51 countries were examined. It was found that extraversion, openness to experience and agreeableness measured at the national level were significantly and positively correlated with national IQs; however, in the regression model only the former two were marginally significant. For openness but not extraversion, this corresponds to observations made at the individual level. It was also shown that, taken together, Big Five traits and IQs of various cultures statistically explained 70% of a nation's gross domestic product (GDP) per capita. The most important predictors of economic success were intelligence and extraversion, which proved to be strongly positively related to GDP. Agreeableness and openness to experience, although significantly correlated with GDP, did not statistically explain any additional variance of GDP over and above IQ and extraversion. The question about causality concerning differential variables and a nation's wealth is discussed. The results provide new insights into relationships between personality and intelligence at the country level. However, uncertainty remains about the validity of country-level personality measures. (Contains 4 tables.)