Patients treated with biologic drugs for various-not only dermatological-diseases are growing in number. Biologic drugs applied as a long-term therapy of psoriasis are safe, enable disease remission, and most importantly, help improve the patient's quality of life. It is also crucial to note, that biologic agents decrease patient mortality rate. Much research has shown the unquestionable efficiency of biologic therapies despite their also well-documented rare adverse effects. Due to the growing range of application of these agents, it is critical to keep an observant eye during the monitoring of the patient in case of new disease activity. This study aims to present the case of a female patient treated with etanercept for severe psoriasis arthritis (PsA) who subsequently developed acute sarcoidosis and to examine the risk of serious adverse events.