Essential fatty acids have been hypothesized as important to health, including cardiovascular health, for several decades. These hypotheses have been supported by epidemiologic studies. There have been several trials evaluating the effects of fish oil (omega-3 fatty acid, one of the major essential fatty acids) on hypertension in individuals with hypertension, and those without hypertension or hypercholesterolemia. The overall effect of fish oil has been a small but significant decline in blood pressure, especially in those with hypertension or hypercholesterolemia. Few side effects are reported with fish oil and all are dose dependent; side effects include gastrointestinal upset, fishy aftertaste and, uncommonly, clinical bleeding. Information on the use of omega-3 fatty acids in hypertension requires further study to understand better the appropriate dose and its benefits, specifically with aging. Preliminary data hold promise that small but significant diminution in blood pressure can be attained.