Objective To investigate the change of cardiac structure and function in patients with uremia before and after peritoneal dialysis (PD). Methods Eighty three standard continuous ambulatory peritoneal dialysis (CAPD) patients treated between October 2009 and October 2014 were selected in this study. According to the ultrasound cardiogram before and 6 months after the PD, we analyzed the influence of age, diabetes mellitus, dialysis interval, hemoglobin, serum albumin, serum creatinine, serum calcium and phosphate and parathyroid hormone (PTH) on the cardiac structure and function. Results Hemoglobin increased significantly after PD (P <0.01), while albumin and PTH decreased significantly (P <0.01). The changes in creatinine, triglyceride and cholesterol were not statistically significant (P > 0.05). For CAPD patients, cardiac systolic function did no t obviously change before and after dialysis, while the diastolic function improved obviously after dialysis. Conclusion PD may improve cardiac diastolic function of CAPD patients.