AbstractImmune reconstitution inflammatory syndrome (IRIS) in patients with human immunodeficiency virus (HIV) and Pneumocystis jirovecii pneumonia infection reflects an exaggerated inflammatory response of the host immune system to an antigen, which is temporally related to recovery of the immune system. Clinical manifestations include fever, cough, dyspnoea and hypoxia following the commencement of antiretroviral therapy. Diagnosis is made on clinical and radiological criteria with exclusion of other infective and non‐infective causes. Unrecognized, IRIS may be associated with significant morbidity and mortality. Treatment with corticosteroids often results in prompt recovery. There is limited literature on radiological findings of Pneumocystis jirovecii pneumonia‐associated IRIS. Here we describe cross‐sectional imaging findings of PJP‐IRIS in a patient following commencement of antiretroviral therapy.