Background: Chronic hypertension (CH) and high arterial stiffness (AS) increase the risk of complications during pregnancy, such as superimposed preeclampsia and low fetal growth. Objective: To evaluate the impact of hydrotherapy, a non-pharmacological treatment strategy, on AS in pregnant women with CH. Methods: Cross-sectional study evaluating the effect of a standardized hydrotherapy session on AS in pregnant women with CH and controls. We used the device Mobil-O-Graph® NG to measure blood pressure (BP), heart rate (HR), and AS before and after a hydrotherapy session involving stretching, warming up, strengthening, and relaxation. The level of significance adopted in the statistical analyses was 5%. Results: We evaluated 36 pregnant women, including 12 with hypertension (HG) and 24 controls (CG), aged 30.4 ± 4.8 years and at 29.2 ± 3.3 gestational weeks. Hydrotherapy promoted in both groups a significant reduction in AS assessed by the augmentation index at a HR of 75 bpm (AIx@75