A state of emergency was in force in the North African country until early October, imposed after a jihadist went on a shooting spree at a popular Mediterranean resort in June, killing 38 foreign tourists.
And in March, gunmen stormed the national museum in the capital, killing 21 tourists and a policeman.
But festival director Ibrahim Letaief said the festival, opening just a week after jihadist attacks in Paris left 130 people dead, is an "antidote to violence", as film "tears away the veil of darkness and is the guarantor of the greatest victory over terrorism".
Culture Minister Latifa Lakhdar echoed that sentiment, saying: "Creativity is the greatest way to mark our attachment to life and our battle against those people who would destroy even the most elementary principles of life."
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And Interior Minister Najem Gharsalli insisted that "we have taken the necessary measures to guarantee maximum security, because this event represents the joy of Tunisians and of our guests".
Film-makers from Africa and the Arab world, Arab movie stars and politicians walked down the red carpet to the Bonbonniere theatre for opening night.
The official competition at the festival, which will end next Saturday, includes 17 feature-length films, 13 shorts and 16 documentaries.
"Much Loved", a Moroccan film about prostitution that is banned at home, will be among those featuring in competition.