January 2024—Diffuse parenchymal lung disease is a well-recognized complication of systemic connective tissue disease but rarely arises in patients with psoriasis or psoriatic arthritis, which are poorly understood. Therefore, the authors conducted a study to characterize diffuse parenchymal lung disease (DPLD) associated with psoriasis or psoriatic arthritis, with or without prior immunomodulation. Their pathology consultation files were searched for patients having psoriasis or psoriatic arthritis and DPLD. After excluding cases with active infection or smoking-related DPLD only, 44 patients (22 of whom were women; median age, 60 years; range, 23–81 years) were enrolled in the study. Clinical history and pathology slides were reviewed.