Objective: The study aimed to assess left ventricular systolic and diastolic function in asymptomatic patients with type 1 diabetes mellitus by conventional, 2D speckle tracking and tissue Doppler echocardiography to detect subclinical left ventricular dysfunction in this group of patients before developing overt clinical diabetic cardiomyopathy. Methods: The Study was a case control study that was done on 100 participants who were divided equally into 2 groups, diabetic group and healthy control group. Each group was subjected to full history taking, complete clinical examination, ECG, conventional, tissue doppler and strain echocardiography. HBA1c level was done for diabetic group to detect correlation between diabetic control and GLS%. Results: The 2 groups were compared regarding demographic data, anthropometric measures, blood pressure measures, conventional, tissue doppler and strain echocardiography. There was a highly statistically significant difference between the 2 groups regarding A wave velocity, E/A ratio, AP2C LS, AP3C LS, AP4C LS and GLS with P value < 0.001 and statistically significant difference with deceleration time DT wit P value 0.023. It also revealed that there was a positive significant correlation between duration of diabetes, HBA1c level and GLS% Conclusion: GLS appears to be a good tool for early detection of subclinical LV systolic dysfunction. Long duration and poor control of diabetes mellitus are important factors for developing diabetic cardiomyopathy.