This survey was performed to obtain the basic information for the prevention and management of occupational low back injury (LBI). The subjects of this survey were 952 workers (male, 892 ; female, 60) who had taken occupational LBI in some industries of Pusan area from January 1 to December 31, 1991. Observation period was 2.6 years from the beginning to the end of medical treatment. The obtained results were summarized as follows ; 1. The proportion of LBI workers was 15.9% of the workers who had taken any occpational injuries and 0.32% of all workers in this surveyed area. 2. 8.0% of the workers had taken LBI on the 1st day of employment and 55.2% of the workers were within one year, 91.4% of the workers were within 10 years according to cumulative frequency distribution. 3. Handling of heavy objects was the most common cause of LBI (32.0%) and fall down (26.9%) and slip down (16.3%) were the next in order. 4. The most common causes of both lumbar sprain and HNP were handling of heavy objects and that of lumbar fracture was fall down. 5. The mean duration for medical treatment of LBI workers was 143 days. 6. The total direct compensation cost for LBI workers was 6,736 million Won and the proportion of medical, resting, disability compensation costs were 25.0%, 37.0%, 38.0 % respectively. 7. The percentages of retreated workers and disabled workers were 11.9% (113 persons) and 22.9% (218 persons) of total LBI workers respectively.