Inclusion Criteria:

• - Patients >18 years of age.

• - IPF diagnosis "definite" or "probable" (2011 ATS/ERS guidelines definitions) confirmed by a multidisciplinary team (= minimum of pulmonologist, radiologist, pathologist, all with expertise in IPF).

• - Patients who agreed to participate in the registry and have completed and signed the Informed Consent Form.

Exclusion Criteria:

• - Patients incapable of giving informed consent.

- Patients participating in a clinical trial at the time of inclusion in the registry and whose protocol does not allow participation in another trial

Idiopathic pulmonary fibrosis (IPF) is a chronic disease of unknown etiology, characterized by scar tissue (fibrosis) within the lungs. IPF is one of the most common forms of interstitial lung disease and is associated with substantial morbidity and mortality (average survival of approximately three years from the time of diagnosis)). The epidemiology and natural history of IPF is still not completely understood. Incidence and prevalence of IPF are difficult to determine because uniform diagnostic criteria have only recently been defined. Recent data among subjects aged 50 years or older suggests an age- and sex-adjusted incidence rate ranging from 8.8 cases to 17.4 cases per 100,000 person-years in the USA. In the same population, age- and sex- adjusted prevalence ranged from 27.9 cases to 63 cases per 100,000 persons. Familial form of IPF accounts for 0.5 to 2% of all cases of IPF. Several environmental or occupational exposures seem to be prevalent in the medical histories of patients diagnosed with the disease. The onset of IPF symptoms is slow, but symptoms become progressively worse over time. Breathlessness upon exertion and chronic dry cough are the major symptoms. Gastro-esophageal acid reflux is present in almost 90% of patients with IPF but often occurs without symptoms. Auscultation of the lungs reveals early inspiratory crackles, predominantly located in the lower posterior lung zones upon physical exam. Clubbing is found in approximately 50% of patients with IPF. Quality of life of patients with IPF is impacted by the disease. Establishing an accurate diagnosis for the patient who presents with interstitial lung disease is an essential component of management. The recent ATS/ERS/JRS/ALAT recommendations on the diagnosis and management of IPF were developed from a systematic review of the published literature. High-resolution computed tomography (HRCT) scanning has a central role in the IPF diagnostic pathway with formal designation of criteria for an HRCT pattern of Usual Interstitial Pneumonia (UIP). In the correct clinical context, a UIP pattern on HRCT is indicative of a definite diagnosis of IPF without the need for a surgical lung biopsy. IPF presents significant associations with other cardiopulmonary disorders including coronary artery disease, pulmonary embolism, sleep apnea, respiratory infections and lung cancer. In addition, patients with IPF are at risk for 'acute exacerbations'. Acute exacerbation is defined as an acute, clinically significant respiratory deterioration characterized by evidence of new widespread alveolar abnormality. Diagnostic criteria are: previous or concurrent diagnosis of IPF; acute worsening or development of dyspnea typically < 1 mo duration; computed tomography with new bilateral ground-glass opacity and/or consolidation superimposed on a background pattern consistent with usual interstitial pneumonia pattern; deterioration not fully explained by cardiac failure or fluid overload. These acute exacerbations are responsible for 50% of deaths in IPF and may affect previously stable patients. The clinical course of IPF is highly variable and as a result, therapeutic strategies should be highly individualized, based upon the specific patients' medical history and co-morbidities. Pirfenidone and Nintedanib are drugs approved for the treatment of adult patients with mild to moderate idiopathic pulmonary fibrosis in the European Union. In order to complement the data collected in previous studies, we implement a registry to describe the epidemiology and natural history of IPF, as well as the quality of life of IPF patients, and use of health care resources, in Belgium and Luxembourg. This registry will also enable the collection of clinical data of patients treated with Pirfenidone or Nintedanib and other therapies used in the treatment of IPF. The registry will be implemented in collaboration with pulmonologists and expert centers in order to enable the inclusion and follow up of recently diagnosed IPF patients.