Empirical research in the personality field, most of it done in developed countries, supports the notion of sex differences. Much less research has been done in developing countries. The purpose of the present research study was to examine sex differences in personality traits in a Peruvian general population sample. Additionally, we explore acquiescence response bias. The sample consisted of 557 Peruvian residents in Metropolitan Lima, with ages ranging from 16 to 79 years (Mage= 29.7, SD = 10.9). Most respondents were women (333, 60%). Participants filled out the adapted version of the Big Five Personality Inventory. Consistent with previous empirical research done worldwide, results showed higher female than male scores on the Neuroticism personality trait. Moreover, removing acquiescent responders increased the reliability in all dimensions of the BFI. These results contribute to the body of empirical research on sex differences in personality.