BACKGROUND : Esophageal candidiasis (EC) remains one of the most common AIDS defining illnesses in patients with human immunodeficiency virus (HIV) in the era of highly active antiretroviral therapy (HAART), but little is known about factors associated with EC after starting HAART. OBJECTIVES : To describe changes in the use of antimycotic medication, the incidence of EC and factors associated with EC before and after starting HAART. METHODS : Patients from EuroSIDA, a pan-European longitudinal, prospective observational study. Generalized linear models and poisson regression models were used to investigate the relationships. RESULTS : A total of 9,873 patients did not have EC at recruitment, subsequently 537 (15.8%) developed EC. The proportion of patients taking any antimycotic dropped from 18% at January 1995 to 2% at January 2004 ( p < 0.0001); the duration of treatment declined from 10 to 3 months over the same period ( p < 0.0001). There was a 32% annual decline in the incidence of EC (95% CI 30–35%, p < 0.0001). There was a significant annual decline in the incidence of EC pre-HAART in time-updated, adjusted models, (incidence rate ratio (IRR) 0.80, 95% CI 0.76–0.85, p < 0.0001) but not post-HAART (IRR 0.97; 95% CI 0.90–1.06, p= 0.54). Older patients and those with low CD4 counts had the greatest incidence of EC in the post-HAART era. CONCLUSIONS : There has been a marked decline in the incidence of EC between 1994 and 2004. This was accompanied by a decline in markers associated with fungal disease, including use of antimycotics and a decline in duration of treatment. (Am J Gastroenterol 2005;100:1446–1454) [ABSTRACT FROM AUTHOR]