BACKGROUND: Heart rate variability (HRV) is an useful noninvasive tool to assess autonomic nervous system (ANS) function and may provide an insight into the understanding of the role of ANS in the pathogenesis of blood pressure (BP) abnormality in euvolemic continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: In this cross-sectional study, 62 CAPD patients with normal hydration values (assessed by a bioimpedance spectroscopy device) were enrolled from our peritoneal dialysis (PD) unit. Patients were divided into three groups according to their BP: normotension (NT), hypertension (HT), and hypotension (HyT). Spectral analysis of HRV was measured by examination of the average heart rate using standard electrocardiogram in 5 min. RESULTS: The HyT group had the lowest serum urea nitrogen among the three groups (all p < 0.05), and a lower serum potassium and albumin as compared with the NT group (p < 0.05). The HyT group also had the highest total power (TP) and highest frequency power (HF) among the three groups (all p < 0.05), and a lower normalized low frequency power (LF), LF/HF ratio, and a higher normalized HF as compared with the HT group (all p < 0.05). CONCLUSION: Our study suggested that autonomic insufficiency was present in euvolemic PD patients, and hypotensives had a relatively higher parasympathetic activity and blunted sympathetic activity.