Little is known about the effect of immune reconstitution inflammatory syndrome (IRIS) on the long-term clinical outcome. Of 52 opportunistic infections (OI) occurring within one year after the start of HAART in 387 HIV patients, 33 (63%) were classified as having IRIS. The patients with IRIS showed no significant difference in the AIDS event-free survival curve compared with the matched control group without OI and in contrast to non-IRIS OI.