Summary: One of the new groups of drugs that are intensively studied and used in allergology are Janus kinase inhibitors (iJAK) – molecules from the family of non-receptor tyrosine kinases involved in intracellular signal transduction. JAK kinases are part of the JAK-STAT signaling pathway, which is responsible for the conduction of extracellular signals from cytokines, interferons and growth factors. Thus, they play a key role in mediating inflammatory and immunological processes, including those observed in allergic diseases. Therefore, new drugs from the iJAK group are currently being intensively tested, whose current registered use in allergic diseases is limited to atopic dermatitis (AD). However, there are many indications that they can also be effective in other diagnoses, such as asthma, even in inhalation form. In this article, we discuss the latest reports on the use of iJAK in AD and new research suggesting their possible use in asthma.