BACKGROUND: People with multiple sclerosis (MS) have a higher risk of cardiovascular disease than the general population, but the data are limited. Evaluation with strain echocardiography, a new echocardiographic method, can provide more objective data to evaluate global and segmental left ventricular systolic functions. Left ventricular Global Longitudinal Strain (GLS) may be useful in demonstrating subclinical myocardial dysfunction in MS, therefore we planned such a study. We aim to evaluate LV functions with GLS obtained with basal tissue doppler in people with MS. MATERIAL AND METHODS: A comparison of the demographic laboratory and echocardiographic findings of the multiple sclerosis patients with strain echocardiography records registered in our hospital and the control group with similar age and gender was performed. 80 RRMS patients and 65 control group were compared. Those with another chronic disease, those who received exacerbation treatment within the last month, those outside the age range of 18-65, and other forms of progressive MS were excluded from the study. RESULTS: GLS scores was significantly lower in the MS group(-17.05 ± 1.33 vs.18.99 ± 1.08, p <
0.001). The optimal GLS score predicted poor LV functional status in people with MS with high EDSS scores with cut-off value ≤ 17.10, sensitivity of 73%, specificity of 58% [AUC: 0.652 95% CI, (0.531-0.773), p = 0.023]. It was observed that as the EDSS score increased, that is, in the presence of worse clinical condition, the GLS score decreased (r = -0.245, p = 0.003). CONCLUSIONS: We think that strain echocardiography may be useful in demonstrating subclinical myocardial damage in people with MS. We found that as the EDSS score, that is, the severity of the disease, increases, the subclinical effect on cardiac functions increases.