The paper aimed to investigate the impact of self-confidence on EFL Sudanese tertiary level students. The sample of the study consisted of 221 (male and female) students, department of English language at El-Imam El-Mahdi University and White Nile College for Science and Technology in the White Nile State for the academic year 2013/2014. It is a mixed methods research design "mixing both quantitative and qualitative methods". A descriptive-correlation design was employed to find out the relationship between self-confidence, academic performance and oral communication. A student's questionnaire and a teacher's interview with teachers of English language who teach oral communication were used for data collection. The data was analyzed by using a variety of statistical methods which included percentages, mean, degree of freedom, sig. (2-taild), Presumptive mean, standard -deviation, Pearson Correlation coefficient, Spearman rank correlations, Spearman- Brown equation, two way ANOVA, T- test, the equation of Cronbach's Alpha and the statistical package for the social sciences (SPSS) for the analysis of the data. The findings revealed a positive, significant correlation between self-confidence, oral communication proficiency and academic performance. The students who scored high in the self-confidence questionnaire also had high scores in oral communication test and academic performance. The study also revealed that there are no statistically significant differences between self-confidence and gender or age of EFL learner. The study concluded with some recommendations which offered to EFL learners, Teachers of English language, administrations of universities, curriculum designers in order to help in directing less confident students to better learning performance. Finally, Further researches were suggested in relation to the impact of personality traits on foreign language learning.