Hypertension raises the risk of cardiovascular consequences to two-fold or three-fold. The incidence of hypertension is increasing worldwide. Genetic causes of blood pressure are estimated to cause half of the hypertension effect, but the genes behind this are still fairly unclear. Polymorphisms in gene STK39 (serine/threonine kinase) have in some studies been associated with hypertension, but results have differed according to genetic population. We screened the STK39 polymorphism rs6749447 in a Finnish cohort to see if it was associated with hypertension.The study included 447 hypertensive cases and 771 controls. All participants were 50-year-old Finnish patients and the data was collected from the Tampere adult population cardiovascular risk study (TAMRISK). Genotypes were determined by polymerase chain reaction using DNAs extracted from buccal swabs.The risk for hypertension among G-allele carriers was 1.4-fold compared with controls (P = 0.006, 95% CI = 1.10-1.79). The genetic effect of the G-allele was even more significant when the strong effect of BMI on hypertension was taken into account: for normal weight patients (BMI < 25) the risk was two-fold (P = 0.003, 95% CI 1.3-3.1) and for normal weight or slightly overweight patients (BMI < 30), the risk was 1.6-fold (P = 0.001, 95% CI 1.2-2.2).In conclusion, there was a significant association between STK39 genetic variant rs6749447 and hypertension in a Finnish cohort.