Hypertension is a risk factor for diseases such as stroke, heart and kidney disease. Phosphodiesterase (PDE) enzymes play a significant role in regulating inflammation and there is some association between increased inflammatory cell mediators and development of hypertension. Previous research has shown the single nucleotide polymorphism (rs702553) on the PDE4D gene to be associated with stroke and carotid atherosclerosis. This research analyzed the association of rs702553 with baseline mean arterial blood pressure (MAP) in a subset of the African American Study of Kidney Disease and Hypertension Cohort. Data analysis identified baseline diuretic use as an interaction term in the association between this polymorphism and MAP. Compared with participants with AA/AT genotypes, those with a TT genotype at rs702553 had significantly lower baseline MAP among study participants on a diuretic (P=0.02). To our knowledge, the influence of rs702553 on final PDE4D gene expression has not yet been studied. Additional clinical and in-vitro studies are needed to better understand the biological mechanisms from gene expression to enzyme translation that affect blood pressure.