The experience with anti-TNF agents is relatively short; and with time, we are learning more about the frequency of occurrence of different adverse events as the original trials were either too small or too brief. We report a case series of four patients who suffered from chronic inflammatory arthritis [rheumatoid arthritis (n = 3) and psoriatic arthritis (n = 1)]. Their inflammatory arthritis remained refractory to increasing doses of methotrexate up to 20 mg weekly and required an advance in treatment to TNF antagonists. However, within a few weeks of commencing these patients on adalimumab, they developed newly diagnosed recurring sinusitis. All these patients were assessed by otorhinolaryngologists, and had clinically confirmed diagnosis. The sinusitis remained refractory to standard medications; however, it resolved after the discontinuation of adalimumab. Although FDA and Irish Pharmaceutical Health Association describe that adalimumab use increases the risk of non-serious infections marginally and most of the patients continued on Humira (adalimumab) after the infection was resolved, however, our recent observation raises the concern of probable higher incidence.