An experimental study is conducted on heat transfer in a rotating serpentine passage with rib-roughened walls under uniform wan heat flux. Seven roughness configurations are tested to determine their effects on convective heat transfer enhancement. Results are obtained for heat transfer distributions which are compared with those having smooth surfaces. It is revealed that rotation, roughness and the angle-of-attack of ribs have significant influences on the heat transfer performance with 45PR having the best enhancement in both stationary and rotating cases. The flow mechanism in a rib-roughened passage is proposed to explain its effect on heat transfer performance.