Pneumocystis jirovecii colonization has been associated with non-acquired immune deficiency syndrome (AIDS) pulmonary comorbidity. We used spirometry to measure pulmonary function and analyzed oral wash specimens by quantitative polymerase chain reaction (PCR), targeting the large mitochondrial ribosomal subunit. For sensitivity control, a blinded subsample was subjected to touch-down PCRs, targeting both large and small ribosomal subunits and the major surface glycoprotein. Pneumocystis jirovecii deoxyribonucleic acid (DNA) was detected in 1 of 156 (95% confidence interval, .1%-3.5%) virologically suppressed human immunodeficiency virus (HIV)-infected individuals confirmed by all PCR methods. Thus, prevalence of P jirovecii colonization was low and unlikely to be a major cause of pulmonary comorbidity in this group of well treated HIV-infected individuals.