The study investigated linguistic politeness in ten viva voce sessions occurring in two universities in Iran. The model of politeness which was proposed by Brown and Levinson (1987) was drawn upon in the study to analyze academic talk in the review context of viva sessions. Particularly, the study focused on negative politeness strategies, which are used to attend the 'negative face' of the speaker and the hearer, due to the formality of the context. Of the negative politeness strategies which were used, 'give deference', 'hedging' and 'impersonalization' were found to be the most frequent strategies. Type of genre and the institutionality of discourse had a robust impact on almost every instance of talk, including politeness strategy choice. While raising our awareness of academic discourse in Persian, the results of the study could help foster interpersonal communication between the peers and academic members to enjoy a more pleasant social world.