Because of its frequency and consequences on professional life, low back pain (LBP) represents a real health care problem. Our study is aimed at determining the prevalence of LBP among hospital staff, analyzing the medical and professional consequences as well as investigating into the factors associated to this health problem. We have conducted an inquiry among 350 employees at Fattouma Bourguiba teaching hospital. The employees have answered a pre-established questionnaire including 51 items. The cumulative life-prevalence was 57.7% of the cases. The annual prevalence was 51.1% of the cases. Chronic LBP prevalence was 12.8% of the cases. Medical care was required in 61.9% of the cases. Radiological explorations were performed in 45% of the cases. Sick leave was observed in 26.1% of the cases and an occupational change was necessary in two cases. Factors associated to LBP were age (P <0.01), female gender (P = 0.024), high BMI (P = 0.01), the fact of being married or divorced (P < 0.01), smoking (P = 0.016), past medical LBP history (P < 0.0001), extra professional activity (P < 0.01), migraine (P < 0.001), years' service (P = 0.007) as well as heavy weight lifting (P = 0.008). Exercise is rather a protecting factor against LBP (P = 0.019). The prevalence of LBP among hospital staff as well as the socio-professional drawbacks is important. Many factors are associated to LBP urging medical teams to take some preventive measures to reduce this affliction.