Ben Lakhdar graduated in 1968 from the University of Pierre and Marie Curie in France. She earned her Doctor of Philosophy from the same university in 1978 with a thesis entitled "Application à l"étude de la raie 4047Å de mercure de la méthode à balayage magnétique" (study of the line shape of 4047Å mercury line using a tunable magnetic field).
She earned in 2005 the L’Oréal-United Nations Educational, Scientific and Cultural Organization Awards for Women in Science. She went back to Tunisia to became professor in 1982 at the Tunis University and served as director of the Laboratory of Atomic Molecular Spectroscopy and Applications (LSAMA).
She was elected in 1992 to the Islamic World Academy of Sciences. She is a fellow of the African Academy of Science since 2006. She became senior associate member at the Abdus Salam International Centre for Theoretical Physics (International Centre for Theoretical Physics). She earned in 2005 the L’Oréal-United Nations Educational, Scientific and Cultural Organization Awards for Women in Science for "experiments and models in infrared spectroscopy and its applications to pollution, detection and medicine".
She was a founding member of the Tunisian Physics Society and a founding member of the Tunisian Astronomy Society.
