A 79-year-old female had been treated with tocilizumab, methotrexate, and prednisolone for 11 months before the first visit to our hospital. After the 10th administration of tocilizumab, she began to complain of dyspnea on exertion and general fatigue. At the time of her first visit, chest computed tomography revealed bilateral diffuse ground-glass opacity and confluent nodules in the right lower lobe. Pneumocystis jirovecii DNA was detected in the bronchial lavage and Cryptococcus neoformans antigen was positive in the serum. We diagnosed her as pneumocystis pneumonia and cryptococcosis. Clinical findings suggesting infectious diseases, such as fever, elevation of C-reactive protein (CRP), and leukocytosis, were not apparent because of the anti-inflammatory effects of tocilizumab and myelosuppression induced by methotrexate. One month after cessation of tocilizumab and methotrexate, CRP increased without prominent deterioration of radiological findings and respiratory status. However, CRP decreased spontaneously along with improvement of the chest radiograph.