Background: Myocardial injury is neither limited to the acute Coronavirus disease 2019 nor moderate-to-severe cases. Objectives:  This study aimed to evaluate the relationship between right ventricular diastolic dysfunction and post- Coronavirus disease 2019 cardiovascular sequelae in young adults with mild disease. Patients and Methods: This study recruited 150 young adults (between 18 and 30 years) who were classified into three equal groups: Group A included 50 patients who sustained cardiac symptoms 12 to 14 weeks following mild Coronavirus disease 2019. Group B included 50 patients who did not show cardiac symptoms 12 to 14 weeks following mild Coronavirus disease 2019. Group C included 50 gender-matched healthy subjects of similar ages without previous Coronavirus disease 2019. Each subject underwent a detailed transthoracic echocardiographic study to detect right ventricular diastolic dysfunction by measuring the tricuspid valve E/A ratio, tricuspid deceleration time, tricuspid E/e' ratio and tricuspid e'/a' ratio.  Results: Right ventricular diastolic dysfunction was higher in group A (80% versus 30% versus 0%, p < 0.001). Tricuspid valve e'/a' was lower in group A (0.86 ± 0.2 versus 1.08 ± 0.2 versus 1.44 ± 0.28, p < 0.001) while tricuspid valve E/ e' was higher (6.7 ± 1.1 versus 3.25 ± 3 versus 3.04 ± 0.36, p < 0.001). Post- Coronavirus disease 2019 patients with right ventricular diastolic dysfunction had a higher right ventricular basal diameter, higher right ventricular systolic pressure, lower right ventricular tricuspid annular plane systolic excursion, and lower fractional area change. Conclusions: After recovery from mild Coronavirus disease 2019, some of young adults had right ventricular diastolic dysfunction, which was more prevalent in those with post- Coronavirus disease 2019 cardiac symptoms.