Introduction: Rhythm disorders (RDs)  or arrhythmias are poor prognostic factors during heart failure (HF). Our objective was to study the frequency of rhythm disorders presented by patients treated for HF in Parakou, Benin in 2017. Methods: This was a cross-sectional, descriptive and analytical study. It consisted of a systematic recruitment of all patients admitted for heart failure in the cardiology units of the city of Parakou from March to August 2017. The diagnosis of RDs was made by cardiac auscultation completed by electrocardiographic recording (standard and Holter over 24 hours). The Lown classification was used to describe the severity of ventricular TRs. The threshold for significance was p < 5%. Results: A total of 83 heart failure patients aged 61.47 ± 15.97 years with a sex ratio of 1.08 were selected. Arrhythmia was detected by auscultation in 20.48%; by standard electrocardiogram (ECG) in 25.83% and by Holter ECG in 97.59% of patients. Among the arrhythmias detected by Holter ECG, 81.48% were atrial, including 28.79% of atrial fibrillation. RDs was ventricular in 90.12% of which 47.95% were severe. Left ventricular systolic dysfunction was significantly associated with ventricular arrhythmias. On the other hand, the frequency of ventricular arrhythmias was not associated with the severity of the HF according to the NYHA classification. Conclusion: In Parakou, RDs are frequent in patients with HF. Holter ECG should be included in the follow-up of heart failure patients in order to improve their management.