Heart failure (HF) is associated with a wide range of comorbidities that negatively impact clinical outcomes and cause high economic burden. We aimed to evaluate the frequency and burden of comorbidities in HF patients in Türkiye and their relationships with patients' demographic characteristics.Based on ICD-10 codes in the national electronic database of the Turkish Ministry of Health covering the entire population of Türkiye (n = 85,279,553) from 1 January 2016 to 31 December 2022, data on the prevalence of comorbidities in HF patients were obtained. The frequency and burden of comorbidities were analyzed separately by age groups, sex, and socioeconomic status (SES).Between 2016 and 2022, there were 2,722,151 patients (51.7% female) of all ages who were diagnosed with HF. In Türkiye, the most common comorbidities of HF patients were hypertension (HT) (97.6%), atherosclerotic cardiovascular disease (ASCVD) (84.9%), dyslipidemia (59.5%), anxiety disorder (48.1%), diabetes mellitus (DM) (45.2%), chronic obstructive pulmonary disease (COPD) (43.6%), anemia (40.6%), and atrial fibrillation (AF) (37.1%). Female patients had higher rates of anemia, DM, HT, and anxiety disorders, while male patients had higher rates of ASCVD, COPD, and dyslipidemia. The most common comorbidity in patients under 20 years of age was congenital heart disease (52.3%). More than 90% of HF patients had ≥2 comorbidities. HF patients with ≥5 comorbidities increased from 18.1% in the group aged 20-49 years to 38.3% in the group aged 50-79 years. Comorbidities were similar across SES groups.The most common comorbidities in cases of HF in Türkiye are HT, ASCVD, dyslipidemia, DM, COPD, anemia, and AF, respectively, and more than 90% of patients have ≥2 comorbidities. While ASCVD and dyslipidemia were more common in male patients, anemia, DM, and anxiety disorders were more common in female patients. The number of comorbid conditions increased with advanced age.