This study aimed to explore the influence of student motivation and student performance through teaching speaking skills and the benefits of private instruction among secondary school students in one private school in Phnom Penh, Cambodia. Several significant drawbacks for students learning English speaking skills affect their motivation and performance. Students lose confidence in producing vocabulary and structure in their speaking. This research uses quantitative methods. Correlation coefficient and P-value are applied to measure the effect of each variable. Student motivation and performance findings are well related to learning English speaking skills based on a statistically significant positive correlation between speaking teaching and student motivation r = 0.64 with vital statistical significance (p<0.01). Also, a statistically significant positive correlation exists between teaching English speaking and student performance; r = 0.78, with vital statistical significance (p<0.01). In addition, a positive correlation between teaching English speaking and student motivation is statistically significant. r = 0.43, with a high level of statistical significance (p<0.01). The main findings show a correlation between speaking skills, student motivation, and corresponding student performance. For further studies, it could investigate critical variables such as teaching spoken English to students. In addition, if possible, the new theory adapted should be self-theory, goal theory, or mixed methods by increasing the sample size and target locus.