This paper presents the measurement of 3-D (three-dimensional) flame geometric parameters based on optical fiber imaging and tomographic techniques. Two identical CCD (Charge-coupled Device) cameras coupled with eight imaging fiber bundles are used to capture the 2-D (two-dimensional) images of a burner flame concurrently from eight different directions around the burner. An optical tomographic algorithm LFBP-SART is utilized to reconstruct the cross-sections and generate a complete 3-D model of the flame. A set of geometric parameters, including length, volume, surface area and circularity, are then determined from the model generated and used for characterizing the flame. The proposed technical approach is firstly evaluated using an LED (light emitting diode) tube with known dimensions, and then on a gas-fired combustion rig. The results obtained demonstrate that the proposed algorithms are effective for measuring the 3-D geometric parameters of a burner flame over a range of combustion conditions.