Since "English has become the lingua franca for academic interaction of learners and academics" (Koo, 2009, p. 77), the development of the EFL learners' oral performance proficiency constitutes the central interest of current English language teaching methodologists and practitioners. The importance of speaking as a productive skill has been echoed in the literature. Indeed, it is viewed as a crucial "part of the curriculum in language teaching … and …an important object of assessment as well" (Luoma, 2004, p. 1). Thus, the prime aim of this study is to explore the prevailing conceptions and actual practices of the assessment of EFL learners' speaking skills at the tertiary level. The respondents of the current research were 20 instructors who taught at the Higher Institute of languages in Gabes and at the Faculty of Arts and Humanities in Sfax, Tunisia. To collect the necessary data, a questionnaire survey was utilized. Then, the obtained data were analyzed using SPSS package. The findings revealed that the teachers' conceptions of assessment are directed towards the development of the learners' speaking skills. Despite the existence of a number of hardships, the teachers' classroom teaching practices revealed a compete reliance on authentic, ongoing, organized and thoughtful oral language assessment procedures which were meant to sustain and boost the learners' oral skill achievements.