The objective of this study was to determine the long-term survival pattern and variables affecting long-term survival and complications occurring during follow-up of patients with Eisenmenger syndrome. A retrospective study of patients diagnosed with Eisenmenger syndrome were followed up. A tertiary care centre was used and it provided superspeciality services in various disciplines. The subjects included 201 patients with Eisenmenger syndrome--diagnosed by a combination of echocardiography and a peripheral arterial oxygen saturation study and/or cardiac catheterisation with or without angiocardiography--worked up and followed up for variable duration over a period of 16 years from 1976 to 1992. One hundred nine patients were females and 92 were males--age of presentation varied from 3 months to 62 years (mean +/- standard deviation 19.23 +/- 12.62 years). A total of 12 different anatomic lesions were seen--the most common three being ventricular septal defect (33.33%), aterial septal defect (29.85%), and patent ductus arteriosus (14.23%). History, physical examination, chest skiagram and electrocardiogram established only the presence of pulmonary arterial hypertension except where differential cyanosis indicating ductus was discernible or the degree of splitting of second heart sound provided some clue to the level of shunt. Contrast echocardiography, completed in 25.4% established the level of shunt in all patients. In others the diagnosis was confirmed by cardiac catheterisation. Twenty patients died during a mean follow-up period of 54.6 +/- 54.47 months. Sudden cardiac deaths (30%), congestive heart failure (25%) and haemoptysis (15%) were the most predominant causes of death. Only one patient died during puerperium.(ABSTRACT TRUNCATED AT 250 WORDS)