Pulmonary arterial hypertension (PAH) is a known complication of rheumatologic diseases, but it is only rarely associated with adult-onset Still's disease (AOSD). We describe the case of a 30-year-old woman who presented in a pulmonary hypertension crisis and was found to have underlying AOSD with PAH and nonspecific interstitial pneumonia (NSIP) with a course complicated by macrophage activation syndrome (MAS). She dramatically improved with steroids, cyclosporine A, and anakinra, with total resolution of the MAS and significant improvement of her pulmonary arterial pressures. While there are only select case reports of AOSD associated with PAH, this is the first reported case of (1) AOSD complicated by both PAH and MAS and (2) AOSD complicated by biopsy-proven NSIP. Clinically, this case highlights the efficacy of immunosuppressive agents in the treatment of PAH and MAS from underlying AOSD and supports their use in this setting.