To investigate the relationship between psoriasis and interstitial pneumonia (IP).We analyzed the clinical data of patients with psoriasis treated with biologic agents from June 1, 2008, to June 30, 2017, retrospectively. Chest computed tomography was performed in 392 patients before treatment. The clinical characteristics and radiographic findings of these patients were evaluated.Of the 392 patients with psoriasis, IP was detected in 8 patients (2%). Bilateral ground-glass and/or irregular linear (reticular) opacity in the lower lung zone was the most common chest computed tomography finding. Five of the 8 patients with IP were treated with anti-interleukin (IL) 12/IL-23 or IL-17 antibodies, leading to decreased or stable IP activity.Interstitial pneumonia was detected in 2% of patients with psoriasis who needed systemic treatments. Ground-glass and/or irregular linear (reticular) opacity in the bilateral lower lobes was characteristic of IP with psoriasis. The IL-23/IL-17 axis may play important roles in the pathogenesis of IP in psoriasis.