This single arm, post-authorisation study is designed to evaluate the long-term safety of pirfenidone in participants with IPF. The enrolment of participants will be completed within approximately 24 months. Participants will receive pirfenidone according to the physician discretion and will be followed for 2 years. Treating physicians will collect pre-specified data at the baseline and every 3 months thereafter, for the duration of the participants' participation in study.

Inclusion Criteria:

• A clinical decision has been made, prior to study enrolment, to prescribe Esbriet
• Participants who are newly prescribed Esbriet therapy
• Initiation of Esbriet therapy is not more than 30 days prior to study enrolment

Exclusion Criteria:

• Participants receiving an investigational agent defined as any drug that has not been approved for marketing for any indication in the country of the participating site
• Participant has received Esbriet therapy 30 days or more prior to current treatment course (e.g., prior participation in clinical trials)
• Participant has any contraindication for the use of Esbriet, according to the current local version of the Summary of Product Characteristics (SPC)

Participants receiving treatment for IPF with pirfenidone according to the physician's discretion