OBJECTIVE: The purpose of this study was to examine the immediate effects of spinal manipulative therapy (SMT) on trunk proprioception in subjects with asymptomatic chronic low back pain (CLBP) and determine if those effects lasted 1 week. METHODS: This unbalanced randomized controlled crossover design examined 33 subjects with CLBP. Proprioception was tested via joint position sense, threshold to detect passive motion (TTDPM), direction of motion (DM), and force reproduction. Each subject received lumbar manipulation or a sham procedure followed by proprioception retest. This procedure was repeated 1 week later using the opposing treatment. Subjects receiving SMT in the second session returned a third time receiving the sham procedure again. RESULTS: Spinal manipulative therapy produced an effect for TTDPM in the manipulation first group (P = .008), the sham procedure produced an effect for joint position sense in the sham first group (P = .005). Spinal manipulative therapy had a 1-week effect for the manipulation first group (P = .006). No effect was noted for either DM or force reproduction. CONCLUSIONS: Results suggest SMT had minimal immediate effect on trunk proprioception. The effects noted occurred in session 1, implicating learning as a potential source. Learning, from repetitive proprioception training, may enhance neuromuscular control in subjects with CLBP before the use of therapeutic exercise. Subjects showed smaller deficits than previously reported for TTDPM or DM, suggesting proprioception deficits may correlate with pain level.