This study investigates interpreting directionality and interpreting competence of undergraduate interpreting students. It tried to answer the following questions: (i) Is there a significant difference between the beginners and advanced students' skills in Liaison interpreting from English to Arabic and Arabic to English, with Arabic as their L1 and English as their L2, i.e., which direction is easier? (ii) Is there a correlation between English-Arabic and Arabic-English interpreting competence of beginners and advanced students? Results showed a correlation between students' ability in English-Arabic and Arabic-English interpreting for both groups. The interpreting test median and mean scores of advanced students show that they are more competent in English-Arabic than Arabic-English interpreting. This means that Arabic-English interpreting is more difficult for advanced students whereas beginners have comparable abilities in both directions. On the contrary beginners have comparable ability in both directions. Comparisons of beginners and advanced students using ANOVA showed no significant differences between both groups in their interpreting competence, i.e., both groups have comparable interpreting competence although the advanced group took more interpreting and translation courses. The factors that affect Arabic-English and English-Arabic interpreting competence and recommendations for developing student interpreting competence in both directions are given.