Path analysis was used to test the influence of writing self-efficacy, writing apprehension, and writing aptitude on the essay-writing performance of 181 ninth-grade students. A model that also included gender accounted for 53% of the variance in performance. As hypothesized, both aptitude and students' self-efficacy beliefs had strong direct effects on performance. Aptitude also had a strong direct effect on self-efficacy, which largely mediated the indirect effect of aptitude on performance. Self-efficacy had a strong direct effect on apprehension, which, in turn, had a modest effect on performance. Girls and boys did not differ in aptitude or performance, but girls reported lower writing self-efficacy. Native English-speaking Hispanic students had lower aptitude and performance scores, lower self-efficacy, and higher apprehension. Results support the hypothesized role of self-efficacy in Bandura's (1986) social cognitive theory. © 1996 John Wiley & Sons, Inc.