Changes in blood flow influence the structure, function, mechanical properties, and remodeling of arteries. The objective of the present study was to investigate the role of increased blood flow on the biaxial incremental elastic moduli of the porcine RCA and to determine the micro-structural basis for the changes in moduli. We hypothesized that an increase in right coronary artery (RCA) flow will lead to increased stiffness in conjunction with remodeling of elastin and collagen in the vessel wall. The control and experimental groups consisted of five RCA vessels each. The RCA of the experimental group was exposed to 4 weeks of flow-overload in right ventricular hypertrophy (RVH) induced by pulmonary artery banding. Stress-strain relationships were determined and the incremental elastic moduli were derived in the circumferential, axial, and cross directions. The results show a significant increase in the elastic moduli in the circumferential (262.7 ± 15.7 vs. 120.2 ± 12.4 kPa; P < 0.001), axial (177.8 ± 25.5 vs. 100.3 ± 11.9 kPa; P = 0.025) and cross directions (104.8 ± 8.2 vs. 68.2 ± 8.6 kPa; P = 0.016) of the experimental RCA as compared to controls. Multiphoton microscopy was used to assess the changes in elastin and collagen content in the media and adventitia of the vessel wall. We found a significant increase in elastin and collagen area fraction particularly in the adventitial layer. These data suggest stiffening of the vessel wall as a result of increased elastin and more predominantly collagen.