Objective. To quantify gait impairments in women with pregnancy-related pain in the pelvis which persisted post-partum. Design. Nine patients and nine healthy subjects were studied during treadmill walking at different velocities. Background. Walking problems in patients with pregnancy-related pain in the pelvis have been known to exist for a long time. To date, no quantitative gait studies have been conducted in this population. Methods. Maximum attainable walking velocity was determined, amplitudes of pelvic and thoracic rotations were calculated, and spectral analysis was used to assess the harmonicity of these rotations. Coordination between pelvic and thoracic rotations was characterized as mean relative Fourier phase and weighted coherence. Results. Maximum attainable walking velocity was highly variable between patients, but on average significantly lower than in healthy controls. Moreover, patients had a significantly lower mean relative Fourier phase (again, highly variable) and higher weighted coherence. The other parameters did not differ significantly between groups. Conclusions. Coordination between pelvic and thoracic rotations in the transverse plane was affected in patients with pregnancy-related pain in the pelvis. Individual patients may apply different strategies during walking to cope with the underlying problems.