Background: Thyroid hormones play an important role in cardiac tissue function. Therefore, it is important to understand the relationship between thyroid hormone levels and cardiac disorders. Objectives: The present study aimed to assess the relationship between normal serum level of thyroid hormones and left ventricular systolic and diastolic dysfunction. Methods: In this cross sectional descriptive retrospective study, 391 patients were selected. They were referred to the Rajaie Cardiovascular Research Center, Tehran, Iran from 2019 to 2021. After extracting echocardiographic and laboratory data from the clinical records, the parameters affecting the left ventricular systolic and diastolic dysfunction were analyzed using statistical software. Results: The mean age of patients was 41 ± 12.8 years. Among them 58.1% of all patients were female. Tricuspid regurgitation (TR) severity had a significant relationship with thyroid stimulating hormone (TSH) level (P = 0.02). End diastolic interventricular septum thickness (IVSD) was inversely associated with thyroxin4 (T4) level (P = 0.04). Mitral valve inflow deceleration time (MVDT) was inversely correlated with thyroxin3 (T3) (P = 0.04). Left ventricular ejection fraction (LVEF) was inversely related to TSH level and end diastolic right ventricular internal diameter (RVIDd) was directly related to TSH (P = 0.05). Conclusions: Thyroid hormone levels in the normal range can be associated with the tricuspid regurgitation severity, end diastolic right ventricular internal diameter (RVIDd), mitral valve inflow deceleration time (MVDT), and. end diastolic interventricular septum thickness (IVSD). Due to the high prevalence of heart disorders, information on thyroid hormone levels can be helpful in the identification and timely treatment of these disorders.