/Objective: Sleep-disordered breathing (SDB) may change from the acute to stable phase of some cardiovascular disorders, but little is known whether these dynamic changes also exist in pulmonary embolism (PE). This study aimed to analyze the changes in the apnea-hypopnea index (AHI) from the acute to stable phase of PE as well as the factors associated. We conducted a prospective, longitudinal and multicenter study of consecutive adults requiring hospitalization for non-hypotensive acute PE, with a protocol including clinical, imaging (transthoracic echocardiography TTE and computed tomography), blood tests and a sleep study within 48 h of diagnosis of PE. After 3 months of follow-up, the sleep study was repeated. Right ventricular (RV) dysfunction was defined according to TTE criteria. One hundred and eleven patients (mean age SD: 63 15 years; body mass index: 28.4 4.7 kg/m2) were included. The initial AHI was 24.4 (21.8) events/h (AHI≥5: 82.8 %; AHI≥30: 33.3 %). Seventy-seven patients (69.4 %) had RV dysfunction. In the overall cohort, the AHI decreased by 8.7 events/h from the acute to stable phase (24.4/h vs. 15.7/h; p=0.013). Patients with RV dysfunction showed a greater decrease in AHI (mean decrease 12.3/h vs. 0.43/h). In the multivariable analysis a drop of an AHI≥5 events/hour was independently associated with the presence of initial RV dysfunction (hazard ratio 3.9; 95%CI 1.3 to 12.1). In hemodynamically stable patients with acute PE, there is a transient but clinically significant decrease in the AHI from the acute to stable phase, particularly when initially presenting with RV dysfunction. Display omitted •Obstructive sleep-disordered breathing (SDB) events are highly prevalent in patients with acute pulmonary embolism (PE).•The number of obstructive SDB events temporarily increase during the acute phase of PE with concomitant right ventricular dysfunction (RVD).•Clinicians are recommended to perform a sleep study within a stable phase when there is suspicion of obstructive sleep apnea in patients with acute PE and RVD.