The objective of this study is to assess the effects of Global Postural Reeducation (GPR) in patients with ankylosing spondylitis and compare GPR with group conventional segmental self-stretching and breathing exercises. This is a controlled interventional study of 38 patients divided into 2 groups: a GPR group (n = 22) and a control group (n = 16). Both groups were treated for more than 4 months. With the GPR group patients, positions that stretched the shortened muscle chains were used. With the control group patients, conventional segmental self-stretching and breathing exercises were performed. The variables analyzed were pain intensity, morning stiffness, spine mobility, chest expansion, functional capacity (Health Assessment Questionnaire-Spondyloarthropathies-HAQ-S), quality of life (Medical Outcome Study Short Form 36 Healthy Survey-SF-36), and disease activity (Bath Ankylosing Spondylitis Disease Activity Index-BASDAI). Statistical analysis was used with a significance level of P < 0.05. There was a statistically significant improvement for all the parameters analyzed between pre-and post-treatment in both groups. In the intergroup comparison, the GPR group showed a significantly greater improvement in morning stiffness (P = 0.013), spine mobility parameters, except finger-floor distance (P = 0.118), in chest expansion (P = 0.028), and in the physical aspect component of the SF-36 (P = 0.001). The results of this study showed that individual treatment with GPR (overall stretching) seems to have better clinical outcomes than group treatment with conventional segmental self-stretching and breathing exercises for patients with ankylosing spondylitis.