Chronic pain is a major source of human suffering, and chronic low back pain (cLBP) is among the most prevalent, costly, and disabling persistent pain conditions. There is an urgent need for safe and effective treatments for cLBP and a greater understanding of the mechanisms whereby these treatments confer their therapeutic effects. Contemplative practices, including conscious breathing practices, offer a potentially noninvasive, inexpensive, and scalable solution for understanding and treating chronic pain. The primary objective of the proposed pilot randomized controlled trial (RCT) is to examine the safety, feasibility, and acceptability of a 5-day breathing practice that involves conscious connected breathing (no pause between inhalation and exhalation) with brief periods of breath retention in a sample of 30 patients with cLBP. The secondary objective is to explore preliminary clinical efficacy and potential mechanisms of the breathing intervention, compared to a closely matched sham meditation control condition, by examining changes in clinical pain outcomes and potential pain-related psychological, physiological, and behavioral mediating variables. Both interventions will be delivered via an audio recording in order to standardize the interventions across participants and to enhance treatment fidelity. Results from this study will inform the successful design and implementation of a larger RCT.