Introduction: Iatrogenic dural tear with cerebrospinal fluid leakage is a known complication of lumbar surgery of the columna. In the literature, the incidence is 3-16%., Material and Methods: The study was a retrospective, consecutive review of electronic patient records after spinal surgery at the Private Hospital Hamlet. The study covers cases from the 10-month period from September 1, 2007 to June 30, 2008. Data was collected after this period and consists of surgeon-documented dural tears. At the time of surgery, the surgeon was unaware that there would be a subsequent registration. A total of 634 patients had lumbar neural decompressive surgery - 479 patients were treated for spinal stenosis and 155 for prolapsed disc., Results: The incidence of dural tear was 3.9% (25 dural tears in 634 operations). The risk of a dural tear after secondary surgery was 7.9% versus 3.3% for primary (p = 0.02) and the mean age was 65.9 years for patients with dural tear compared with 58.1 years for patients without (p = 0.00). The difference in the mean duration of surgery was significant being 72 minutes in the group suffering a dural tear compared with 56 minutes (p = 0.03) among the remaining patients, and in the former group length of stay was increased by 1.1 day (p = 0.00)., Conclusion: The incidence of iatrogenic dural tear was 3.9%. The incidence of dural tear was doubled in secondary surgery. The duration of surgery increased by 16 minutes and the patients with dural tear were also hospitalized one day longer.