Abstract <p>Pulmonary fibrosis (PF) is a debilitating and lethal illness characterised by extensive lung scarring. Despite substantial research into the aetiology of PF and the consideration of several components, a definitive explanation remains unidentified. The prognosis for the disease remains unfavourable due to few treatment choices and the absence of a cure. Consequently, nanoparticle (NP)-assisted pharmaceutical delivery techniques have emerged as a practical approach for enhancing treatment efficacy and patient compliance. Amongst these, polymer-based NPs stand out for their remarkable ability to regulate the possessions, enabling the customised administration of anti-fibrotic medications to specific lung sites. This is achieved through their unique properties that allow them to target the affected areas of the lungs, thereby reducing systemic side effects and improving treatment outcomes. The present investigation provides updated information on the current status of polymer-based NPs for the treatment of PF, highlighting their potential to transform the field and stimulate additional research. The pathophysiology and conventional therapy of PF are complex and varied. The treatment options, such as pirfenidone (PFD) and nintedanib (NTD), demonstrate limited efficacy and significant adverse effects. The urgent need for innovative therapeutic techniques is clear as they are imperative for significantly improving treatment outcomes and inspiring researchers to contribute to advancing PF treatment. A variety of polymer-based NPs have been assessed for PF treatment, including human serum albumin (HSA) NPs, chitosan (CS) NPs, cyclodextrins (CDs) NPs, hyaluronic acid (HA) NPs, poly(lactic-co-glycolic acid) (PLGA) NPs, and polymeric micelles (PMs). These NPs have demonstrated the ability to improve drug delivery and diminish toxicity in preclinical settings. However, challenges such as the need for a better understanding of their pharmacokinetics and pharmacodynamics, optimising their physicochemical properties, and developing scalable manufacturing processes must be addressed before applying polymeric NPs in clinical settings. These issues require additional study to overcome obstacles and fully exploit their potential.</p> Lay Summary <p>PF is a severe lung disorder characterised by irreversible scarring of lung tissue, resulting in considerable respiratory complications and diminished quality of life. Regrettably, viable therapeutic choices for this disease are constrained, resulting in minimal options for patients. This study investigates the promising potential of engineered polymeric NPs developed from natural or synthetic materials as an innovative option for targeted drug delivery to the lungs. These NPs precisely deliver anti-fibrotic drugs to the damaged regions of the lungs and reduce systemic adverse effects. This review analyses several polymeric NPs and their effectiveness in enhancing drug delivery by addressing issues related to drug uptake and mucus barriers in the pulmonary system. Our findings suggest that these innovative delivery technologies could enhance the treatment approach for PF, leading to improved patient outcomes. We emphasise the essential requirement for further study to comprehensively determine the safety, efficacy, and practical applicability of these NPs in clinical settings.</p> Graphical Abstract <p></p>