Purpose: The purpose of this study was to evaluate the correlation between the retinal blood flow (RBF) assessed by the retinal functional imager (RFI) and central macular thickness/volume assessed by a spectral scanning laser ophthalmoscopy/optical coherence tomography (SLO-OCT) system. Methods: Seventeen eyes of 14 consecutive patients with various ocular diseases were examined. Retinal blood circulation characteristics were measured using the RFI. Retinal thickness/volume parameters were obtained by SLO-OCT. Analysis of correlation between RBF velocity and SLO-OCT findings was performed. Results: The analysis of the correlation between RBF and central retinal thickness/volume (5 × 5 mm grid pattern) showed a strong correlation between the average venous RBF velocity and central retinal volume. A linear relationship between the retinal blood velocity in veins and center, middle ring, outer ring and total central squares of macular volume [correlation coefficient 0.86 (p = 0.00001); 0.89 (p = 0.000001); 0.82 (p = 0.0004); 0.85 (p = 0.00001), respectively] has been observed. Arterial blood flow velocity did not correlate with thickness and with central retinal volume. Conclusions: Venous RBF, analyzed by the RFI, significantly correlated with the volume of the central retina, measured by SLO-OCT. Venous blood velocity increased linearly with the increase in the central retinal volume. In this small study, assessment using the RFI provides useful information and may contribute to the further understanding of hemodynamics in the retina blood vessels. The RFI shows promise of being able to analyze retinal hemodynamics noninvasively and may contribute to the further understanding of the relationship between retinal thickening and function.