Background Left atrial (LA) function plays an important role in the maintenance of cardiac output, however, in patients with constrictive pericarditis (CP), whether pericardial restriction and adhesion can lead to LA dysfunction, and the characteristics of LA function remain unclear. The aim of the study is to compare the left atrial (LA) function of patients with CP to that of healthy study participants using speckle tracking echocardiography (STE) and conventional echocardiography. Methods and Results Thirty patients with CP and 30 healthy volunteers (controls) were enrolled in the study. The underlying cause of CP was viral pericarditis in 24 (80%) patients and unknown in 6 (20%) patients. The LA maximum volume (Vmax), LA minimal volume (Vmin), and LA volume before atrial contraction (Vpre-a) were measured using biplane modified Simpson’s method. The LA expansion index (LA reservoir function) was determined as follows: ([LAVmax - LAVmin]/LAVmin) ×100. The passive emptying index (LA conduit function) was calculated as follows: ([LAVmax - LAVpre-a]/LAVmax) ×100, and the active emptying index (booster pump function) was calculated as follows: ([LAVpre-a - LAVmin]/LAVpre-a) ×100. All the patients underwent two-dimensional STE. The LA global systolic strain (S), systolic strain rate (SrS), early diastolic strain rate (SrE) and late diastolic strain rate (SrA) were measured. The LA expansion index, passive emptying index, the active emptying index and the LA global S, SrS, SrE, SrA were found to be significantly lower in patients with CP than in the control participants (P <0.001). LA function was correlated with the early diastolic velocity of the lateral mitral annulus (P <0.05). Conclusions Although left ventricular systolic function was preserved in patients with CP, the LA reservoir, conduit, and booster functions were impaired. Pericardial restriction and impairment of the LA myocardium may play an important role in the reduction of LA function in patients with CP.