An initiative of the National Physicians Alliance, the project titled "Promoting Good Stewardship in Clinical Practice," developed a list of the top 5 activities in primary care for which changes in practice could lead to higher-quality care and better use of finite clinical resources. One of the top 5 recommendations was "Don't do imaging for low back pain within the first 6 weeks unless red flags are present." This article presents data that support this recommendation. We selectively reviewed the literature, including recent reviews, guidelines, and commentaries, on the benefits and risks of routine imaging in low back pain. In particular, we searched PubMed for systematic reviews or meta-analyses published in the past 5 years. We also assessed the cost of spine imaging using data from the National Ambulatory Medical Care Survey. One high-quality systematic review and meta-analysis focused on clinical outcomes in patients with low back pain and found no clinically significant difference in pain or function between those who received immediate lumbar spine imaging vs usual care. Published data also document harms associated with early imaging for low back pain, including patient "labeling," unneeded follow-up tests for incidental findings, irradiation exposure, unnecessary surgery, and significant cost. Routine imaging should not be pursued in acute low back pain. Not imaging patients with acute low back pain will reduce harms and costs, without affecting clinical outcomes.