The Italian Network on Congestive Heart Failure (IN-CHF) project, later known as IN-HF Online, was launched in 1995 to provide the Italian cardiology community with a digital tool, standardized across the country, for managing outpatients with heart failure (HF), that enabled the creation of a database for clinical, educational and scientific purposes. During its almost three decades of activity, this observational research program has achieved highly positive scientific results. Indeed, IN-HF fostered professional relationships among individuals working in different centers, established a cultural network for the care of HF patients, periodically updated on the scientific advances, and allowed the assessment of several clinical, epidemiological, and prognostic features. These findings have been published in numerous national and international journals, as summarized in the present overview.