Introduction and objectives: Heart failure (HF) is a major health problem that causes high mortality and hospitalization rates. This study aims to determine the HF prevalence rates in populations aged both ≥18 years and ≥50 years and to assess its association with cardiovascular diseases and chronic kidney disease. Methods: A cross-sectional observational study was conducted in a primary care setting, with a population-based random sample of 6588 people aged 18.0–102.8 years. Crude and adjusted prevalence rates of HF were calculated. The associations of renal and cardiometabolic factors with HF were assessed in both populations using univariate, bivariate and multivariate analysis. Results: The HF crude prevalence rates were 2.8% (95%CI: 2.4–3.2) in adults (≥18 years), and 4.6% (95%CI: 4.0–5.3) in the population aged ≥ 50 years, without significant differences between males and females in both populations. The age- and sex-adjusted prevalence rates were 2.1% (male: 1.9%; female: 2.3%) in the overall adult population, and 4.5% (male: 4.2%; female: 4.8%) in the population aged ≥ 50 years, reaching 10.0% in the population aged ≥ 70 years. Atrial fibrillation, hypertension, low estimated glomerular filtration rate (eGFR), coronary heart disease (CHD), stroke, sedentary lifestyle, and diabetes were independently associated with HF in both populations. A total of 95.7% (95%CI: 92.7–98.6) of the population with HF had an elevated cardiovascular risk. Conclusions: This study reports that HF prevalence increases from 4.5% in the population over 50 years to 10% in the population over 70 years. The main clinical conditions that are HF-related are sedentary lifestyle, atrial fibrillation, hypertension, diabetes, low eGFR, stroke, and CHD.