We conducted a nested case-control study in a cohort of patients initiating antiretroviral therapy (ART) to identify risk factors and common manifestations of immune reconstitution inflammatory syndrome (IRIS) and to validate the Robertson criteria for IRIS prediction. HIV-infected patients at the Tuberculosis Research Centre clinics, Chennai and Madurai, India, initiating ART between July 2004 and June 2005 were prospectively studied. Of 97 patients (62% men, median age 32 years, median CD4 count 63 cells/μL) included, 34 developed IRIS. IRIS was more common in patients with a prior history of tuberculosis (74% versus 52%, P = 0.04), median time to development was 46 days and the sensitivity and specificity of the Robertson criteria to predict IRIS were 91% and 22%, respectively. In this population, IRIS was a common event, more so among patients with prior tuberculosis, and neither the rate of CD4 increase nor the Robertson criteria were useful in predicting its development.