Jallali spent his professional career primarily on the ITF Futures and satellite circuits, reaching a career best singles world ranking of 546.

From 1996 to 2008, Jallali participated in 40 Davis Cup ties for Tunisia and played 67 rubbers in total.

In 2003, Tunisia returned to Group II after a 10-year absence and travelled to Hillerød to play Denmark, where he won the opening rubber of the tie, over Rasmus Nørby in five sets.

[1] By the time he retired he had amassed a team record 39 wins, of which 26 came in singles rubbers.

As a coach, Jallali had stints captaining Tunisia's Davis Cup team and has toured as the private coach of local players, including Ons Jabeur and Malek Jaziri.