Cardiac dysfunction portends a poor prognosis in renal failure and vice versa. Functional abnormalities of heart in patients with renal insufficiency were frequently noted. The aim of this study is to assess the relationship between left ventricular systolic and diastolic function and renal function in patients with various degrees of renal function. This cross-sectional study included 167 patients from our Outpatient Department of Internal Medicine. Left ventricular systolic and diastolic functions were assessed by echocardiography. Clinical and echocardiographic parameters were compared and analyzed. The prevalence of left ventricular ejection fraction (LVEF) <50% was 31.7% and the average value of the ratio of peak early transmitral filling wave velocity (E) to early diastolic velocity of lateral mitral annulus (Ea) was 11.4 ± 6.2. After the multivariate analysis, low systolic blood pressure, rapid heart rate, low albumin, and low estimated glomerular filtration rate (eGFR) (odds ratio = 0.957; 95% confidence interval = 0.929-0.986; p = 0.004) levels were associated with LVEF < 50%. Besides, old age, low albumin, low eGFR (β = -0.172; p = 0.043), and high uric acid levels were associated with high E/Ea. Our findings show a significant correlation between LVEF < 50% and high E/Ea and decreased eGFR.