The effects of sex and personality traits on self-estimates of intelligence were examined in a sample of 302 Austrian adults (143 men, 159 women). Confirming previous research, men had higher self-estimates of logical and spatial abilities than did women, and these differences were partly explained in terms of women's higher Neuroticism scores. Neuroticism (negatively) and Openness (positively) accounted significantly for variances in self-estimates of spatial and logical intelligence. However, sex had stronger direct and indirect effects on self-estimates of intelligence. Sex and personality effects appear to be largely independent. Thus, being male, emotionally stable, and open to new experiences is likely to result in higher self-estimates of spatial and logical abilities.