Background: Motor control exercise (MCE) is used by healthcare professionals worldwide as a common treatment for low back pain (LBP). However, the effectiveness of this intervention for acute LBP remains unclear. Objectives: To evaluate the effectiveness of MCE for patients with acute non-specific LBP. Search methods: We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), four other databases and two trial registers from their inception to April 2015, tracked citations and searched reference lists. We placed no limitations on language nor on publication status. Selection criteria: We included only randomised controlled trials (RCTs) examining the effectiveness of MCE for patients with acute non-specific LBP. We considered trials comparing MCE versus no treatment, versus another type of treatment or added as a supplement to other interventions. Primary outcomes were pain intensity and disability. Secondary outcomes were function, quality of life and recurrence. Data collection and analysis: Two review authors screened for potentially eligible studies, assessed risk of bias and extracted data. A third independent review author resolved disagreements. We examined MCE in the following comparisons: (1) MCE versus spinal manipulative therapy; (2) MCE versus other exercises; and (3) MCE as a supplement to medical management. We used the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach to assess the quality of evidence. For missing or unclear information, we contacted study authors. We considered the following follow-up intervals: short term (less than three months after randomisation); intermediate term (at least three months but within 12 months after randomisation); and long term (12 months or longer after randomisation). Main results: We included three trials in this review (n = 197 participants). Study sample sizes ranged from 33 to 123 participants. Low-quality evidence indicates no clinically important differences between MCE and spinal manipulative therapy for pain at short term and for disability at short term and long term. Low-quality evidence also suggests no clinically important differences between MCE and other forms of exercise for pain at short or intermediate term and for disability at intermediate term or long term follow-up. Moderate-quality evidence shows no clinically important differences between MCE and other forms of exercise for disability at short term follow-up. Finally, very low-quality evidence indicates that addition of MCE to medical management does not provide clinically important improvement for pain or disability at short term follow-up. For recurrence at one year, very low-quality evidence suggests that MCE and medical management decrease the risk of recurrence by 64% compared with medical management alone. Authors' conclusions: We identified only three small trials that also evaluated different comparisons; therefore, no firm conclusions can be drawn on the effectiveness of MCE for acute LBP. Evidence of very low to moderate quality indicates that MCE showed no benefit over spinal manipulative therapy, other forms of exercise or medical treatment in decreasing pain and disability among patients with acute and subacute low back pain. Whether MCE can prevent recurrences of LBP remains uncertain.