The objective of the study was to evaluate the breathing pattern in patients with chronic non-specific low back pain (LBP) and in healthy subjects, both at rest and during motor control tests. Ten healthy subjects and ten patients with chronic LBP participated at this case-control study. The breathing pattern was evaluated at rest (standing and supine position during both relaxed breathing and deep breathing) and while performing clinical motor control tests, i.e. bent knee fall out and active straight leg raise. A blinded observer analyzed the breathing pattern of the participants using visual inspection and manual palpation. Costo-diaphragmatic breathing was considered as optimal breathing pattern. Subjects filled in visual analog scales for the assessment of pain intensity during the tests. At rest, no significant differences were found between the breathing pattern of patients and healthy subjects (P > 0.05). In contrast, significantly more altered breathing patterns were observed in chronic LBP-patients during motor control tests (P = 0.01). Changes in breathing pattern during motor control tests were not related to pain severity (P > 0.01), but were related to motor control dysfunction (P = 0.01).