Background: Left ventricular hypertrophy (LVH) is a common adaptive response in both athletes and hypertensive patients. However, distinguishing physiological from pathological LVH is critical to avoid misdiagnosis and unnecessary intervention. Objective: This study aimed to identify clinical and echocardiographic parameters that differentiate LVH in athletes from that in hypertensive individuals. Subjects and methods: In this observational cross-sectional study, 100 male subjects with echocardiographically confirmed LVH were enrolled: 50 competitive endurance / strength-training athletes and 50 hypertensive patients. All participants underwent comprehensive clinical evaluation and standard transthoracic echocardiography, including speckle-tracking analysis for global longitudinal strain (GLS). LV mass index, wall thickness, diastolic function, and strain parameters were compared between groups. Results: Athletes were significantly younger (35.8 ± 6 vs. 44 ± 6.5 years, p < /em> = 0.004) and taller (177.7 ± 5.8 vs. 174.6 ± 5.3 cm, p < /em> = 0.007). Resting heart rate and blood pressures were lower in athletes (p < /em> < 0.001). Athletes exhibited larger LVEDD (53.9 ± 3.6 vs. 50.3 ± 3.2 mm, p < /em> < 0.001) and higher LV mass (259.4 ± 57.9 vs. 247.6 ± 34.7 g, p < /em> = 0.001), while hypertensive patients showed increased septal thickness (12.93 ± 0.70 vs. 11.70 ± 1.67 mm, p < /em> < 0.001) and relative wall thickness. Diastolic function was better preserved in athletes, as evidenced by higher e′ velocity (13.98 ± 1.74 vs. 9.31 ± 2.08 cm/s, p < /em> < 0.001) and lower E/e′ ratio (5.51 ± 1.34 vs. 9.00 ± 2.27, p < /em> < 0.001). GLS was significantly reduced in hypertensive patients (–17.5 ± 1.2 vs. –18.3 ± 1.8%, p < /em> = 0.036). Conclusion: A combination of clinical features, diastolic function parameters, and myocardial strain imaging effectively differentiates athlete's heart from hypertensive LVH. GLS and diastolic indices offer incremental diagnostic value in distinguishing physiological adaptation from early hypertensive remodelling.