Mastoiditis is an inflammatory process involving the air cells of the mastoid process with inflammation of the bone and periosteum. Since the introduction of effective antibiotic therapy, it is a rare complication of otitis media, but still observed. Recently, the incidence of mastoiditis has started to increase again. This may be due to the development of microbial resistance to antibiotics. It is very important to properly diagnose this condition and then introduce appropriate treatment, because if left untreated or insufficient treated, it can lead to life-threatening consequences. The aim of the study is to describe the case of a 39-year-old patient with latent mastoiditis complicated by septic shock and to present the available diagnostic and treatment methods in this disease entity.