Essential hypertension is an escalating problem for industrialized populations. It is currently seen as a 'complex' genetic trait caused by multiple susceptibility genes the effects of which are modulated by gene-environment and gene-gene interactions. Nevertheless, the success to date in identifying these susceptibility genes has been very limited. A number of candidates has been proposed, but demonstrating consistently the linkage or association with hypertension has been problematic. The data for angiotensinogen is undoubtedly the most extensive and meta-analysis has confirmed a significant association overall, although the risk contributed by this gene appears to be modest (odds ratio of 1.2). Identifying further genes - probably conferring even smaller attributable risks - represents a major challenge for future developments in this area. This contrasts markedly with the success that has been achieved in the past 5 years in solving the molecular genetics of a number of rare familial hypertension syndromes. The true incidences of some of these disorders may be higher than first appreciated, but it is still unclear if the genes for these syndromes also play a part in essential hypertension. A more complete understanding of the genetic basis of essential hypertension should be possible in the coming years using new strategies that take advantage of the information provided by the human genome project. This knowledge will irrevocably change the way we approach this disease in terms of its diagnosis, risk assessment for end-points such as stroke and heart disease, and the customised treatment that might be offered in the future.