Adult-onset Still’s disease (AOSD) is a rare condition diagnosed by a combination of clinical and laboratory features and after ruling out other conditions. Pulmonary manifestations, apart from pleuritis, are uncommon and pulmonary arterial hypertension (PAH) in extremely uncommon. We have described a case of AOSD with severe PAH. There have been rare reports of PAH occurring in AOSD in the literature. Probably, this manifestation may have been understudied, being confined to cases which are symptomatic. A larger study to look at the asymptomatic occurrences of PAH in AOSD may help in unraveling the mystery of this disease.