In the era of highly active antiretroviral therapy (HAART), immune reconstitution inflammatory syndrome (IRIS) has come to present a significant clinical challenge. Following the recovery of memory T cells, latent infections may lead to clinical and laboratory deterioration despite immunological and virological reconvalescence. However, many other forms of complications after induction of HAART, which are not entirely understood, must be included in the entity of IRIS. Here we report a case of a patient complaining of respiratory distress and fever 10 days after initiating HAART. Radiologically and clinically, his findings mimicked Pneumocystis jiroveci pneumonia. However, no infectious agent could be detected, and bronchoalveolary lavage showed a high cell count (90% lymphocytes and 4% eosinophils) consistent with interstitial pneumonitis. He improved dramatically after treatment with oral steroids.