Industrial accidents causing lumbar back strain are frequent and are of major causes of absenteeism. For this purpose, we tried in this study to assess the prevalance of such accidents, to determine the circumstances of their occurence and to point out the various risk professions. For this, we analysed 242 files of lumbar back pathology industrial accidents related. The latter files have been examined by the Tunis medical board authorized to set out the permanent disability rate resulting from industrial accidents and occupational diseases. We noticed a marked male predominance 58% of patients were aged between 41 and 50 years. We observed a predisposition in 19% of all cases. The professional category of operators is mainly concerned. These accidents most frequently occur in the morning at the site of work, often due to the handling of heavy loads. They cause lesions of variable importance, such as slipped disc hernia in 40% of cases. The average duration of absenteeism resulting from lumbar strain is of 237 days a year per patient. After-effects are frequent, notably those of spinal pains and lumbar stiffness. The average rate of permanent partial disability is of 8% (0-45%).