Patients with multiple myeloma (MM) can develop cardiac abnormalities, predisposing them to the development of heart failure, arrhythmias, or infarction with poor prognosis. The purpose of this study is to evaluate the prognostic potential of electrocardiographic (ECG) parameters in patients with MM.This study retrospectively included patients with MM from January 2010 to December 2018 in the First Affiliated Hospital of Xi'an Jiao Tong University. Univariate and multivariate Cox proportional hazard models were conducted to evaluate the relationship between ECG parameters and all-cause mortality in patients with MM.A total of 409 patients were included (mean age 61.3 ± 9.7 years, 59.2% male). The relationship between ECG parameters (including PR interval, voltage, QRS axis, QRS duration, and QTc interval) and all-cause mortality in patients with MM was evaluated. Overall, patients with QTc interval ≥ 400 ms have a significantly higher all-cause mortality compared to those with QTc interval  0.05). Patients with MM and QRS duration ≥ 120 ms had a higher all-cause mortality compared to those with QRS duration  0.05). PR interval, voltage, and QRS axis did not predict mortality.QTc interval was independently associated with all-cause mortality in patients with MM, especially when QTc interval was more than 400 ms in more advanced stages II and III. ECG parameters may provide prognostic potential in patients with MM and aid risk stratification of these patients.