The present study examined inter-ethnic, rural-urban, and sex differences in self-assessed intelligence (SAI) in a Malaysian general population sample. In total, 633 individuals varying in rural or urban location, ethnicity (Malay, Kadazan, and Bajau), and sex (women versus men) provided their self-assessed overall intelligence and ten multiple intelligences. In general, results of a series of univariate analyses of variance showed that urban participants tended to have higher SAI than their rural counterparts and that men reported higher SAI than women. There was also a significant main effect of ethnicity, with Malays generally having lower estimates than Bajaus and Kadazans, respectively. There were few significant interactions between ethnicity, urban-rural location, and sex. These data present the first concurrent investigation of ethnic, rural-urban, and sex differences in SAI, and are discussed in relation to previous theoretical discussions of SAI. (Contains 2 tables.)