This is a review article on the different approaches used to obtain fusion of the lumbar spine. To describe certain conceptual and technical aspects related to the various fusion techniques that are used commonly for lumbar spine disorders and to discuss the expected clinical results. There are differences of opinion among surgeons concerning the preferred method for lumbar spine fusion, whether done for deformity, disease, trauma, or degeneration. A review of the literature combined with personal experience formed the basis of this article. At the present time, analysis of the literature does not indicate that one form of fusion is significantly better than another for degenerative conditions of the lumbar spine. There is recent evidence suggesting better outcomes (as distinct from subjective opinion alone) are obtained after anterior interbody fusion than after posterolateral fusion with internal fixation, despite a higher fusion rate in the latter group. There is evidence that suggests late spinal stenosis adjacent to a fusion is more likely to occur with posterior fusion procedures than with anterior fusion alone. Significant potential complications are associated with all techniques, particularly neurologic damage with posterior interbody fusion, and vascular injury with anterior interbody fusion. Spinal fusion procedures should only be done by surgeons with the necessary training and expertise.