A miniaturized substrate-integrated waveguide (SIW) power divider with embedded filter response and arbitrary power-dividing ratio loaded by open complementary split-ring resonators (OCSRRs) is presented. In the proposed power divider, the miniaturization and filtering response are realized by a pair of OCSRRs, which are etched on the metal cover of the SIW structure. The design procedure indicates that the power division ratio can be adjusted by changing the locations of the output ports. In this study, three miniaturized filtering SIW power dividers with different power division ratios (1:1, 1:4, and 1:8) are implemented to evaluate the performance of the proposed structure on the size reduction. These power dividers (1:1, 1:4, and 1:8) have the overall sizes of 0.31λg × 0.14λg, 0.25λg × 0.17λg, and 0.25λg × 0.18λg, respectively. The measured results also agree well with the simulated results.