We present experimental results obtained with a two-head prototype of a small-animal positron emission tomograph based on resistive plate chamber detectors (RPC-PET). A planar 22Na disk source was imaged. The maximum-likelihood expectation maximization (MLEM) reconstruction of the acquired data yielded a resolution of 0.4mm full width at half maximum (FWHM). Each of the two detectors utilized in this work had an effective front face of 6.4 cm × 6.4 cm and consisted of 5 gas gaps with a total thickness of 5 mm. The data included lines of response (LORs) inclined up to 58 °, demonstrating the parallax-free property of RPC-PET.