Over the past 20 years, the interest of the scientific community was increasingly placed in the field of genetic epidemiology and molecular genetics of blood pressure control. This paper explores references related to essential hypertension, gene and genetic epidemiology indexed in the MedLine health science database during the period 1980-2001. A systematic literature search was performed using selected keywords, such as 'genetic', 'genome' or a combination of words. We considered the study heading and evaluated the time profile of published articles. A total number of 3116 publications was collected and analyzed. Allelic distribution for the most studied polymorphisms of the renin-angiotensin system in different world populations was reviewed and reported together with a detection of their frequency in Italy: essential hypertensive patients (n = 90), healthy unrelated subjects (n = 300). Molecular variants at angiotensinogen (M and T), angiotensin II type 1 receptor (A and C) and angiotensin-converting enzyme (D and I) genes were analyzed by amplified fragment length polymorphism. A significant association was detected by chi2 analysis for angiotensinogen and angiotensin II-type I receptor allele distribution in hypertensive patients, in accordance with previous reports. Genetic data and methods are contributing more and more to epidemiological studies of complex diseases, and their application is influenced by information availability and Genome Project results.