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Background and Importance Pirfenidone and nintedanib are the main antifibrotic agents used for treating interstitial lung diseases (ILD). Although both demonstrate similar efficacy, therapeutic decisions often depend on their safety and tolerability profiles. Real-world evidence is essential to better understand adverse events, treatment adherence, and the need for therapeutic adjustments.Aim and Objectives To assess the safety and tolerability of pirfenidone and nintedanib in patients with ILD, focusing on adverse events (AEs), time to dose reduction, treatment duration, drug switching, and discontinuation rates.Material and Methods A retrospective analysis of electronic health records was conducted from August 2017 to August 2025. Demographic (sex, age) and clinical variables were evaluated. Adverse events were qualitatively classified based on patient reports and clinical documentation.Results In the pirfenidone group (n=103), patients were aged 48–90 years (61% male). Mean treatment duration was 391.45 days, with dose reduction occurring after a mean of 142.75 days. AEs were reported in 60.19% of patients, mainly gastrointestinal (19.42%) and dermatological (8.74%). There were 25 dose reductions, 21 switches to nintedanib, and 3 permanent discontinuations (66.7% associated with AEs).In the nintedanib group (n=112), patients were aged 40–88 years (59% male). Mean treatment duration was 468.30 days, with dose reduction after 257.54 days. AEs occurred in 72.32% of patients, predominantly gastrointestinal (60.71%). There were 46 dose reductions, 15 switches to pirfenidone, and 8 permanent discontinuations (25% of these related to AEs).Conclusion and Relevance Despite a higher incidence of AEs with nintedanib, it showed better tolerability, reflected in longer treatment duration and delayed dose reduction, suggesting improved adherence. Pirfenidone was associated with a higher rate of treatment discontinuation. These findings highlight the importance of continuous pharmaceutical monitoring to characterise the real-world safety profile of antifibrotic therapies and support personalised clinical decision-making.Conflict of Interest No conflict of interest