Pneumocystis jirovecii pneumonia (PJP) is one of the most common causes of respiratory failure in patients with human immunodeficiency virus (HIV) infection, for which the mortality rate is approximately 10%. Spontaneous pneumothorax as a presentation of PJP has been reported with rising frequency, but tension pneumothorax as a presentation of PJP is rare. We reported a case of a middle-aged male with HIV infection who presented to our hospital with acute worsening shortness of breath and was later diagnosed with tension pneumothorax due to PJP. Physicians should suspect pneumothorax in patients with a clinical presentation of PJP who show rapid progressive respiratory deterioration.