This study, the first of the kind in the field of English for specific purposes, examined direct and indirect relationships among English language proficiency, English public speaking (EPS) motivation, motivational intensity, self-efficacy, and EPS achievement. The sample consisted of 189 non-English-major students. The final structural equation model yielded an acceptable fit to the data and explained 23.4% of the variance in EPS achievement. English language proficiency and EPS self-efficacy had both direct and indirect (via, respectively, self-efficacy and motivational intensity) impacts on EPS performance. Ought-to self emerged as the strongest contributor to explaining motivation (R[superscript 2] = 0.90), followed by learning experience (R[superscript 2] = 0.57), and ideal self (R[superscript 2] = 0.32). Implications are discussed.