In this work, effect of Zn doping on the performance of LiMnPO4 is revisited. Samples of pure and Zn-doped LiMnPO4 are synthesized by a new solid-state method, and their structure, morphology and electrochemical behavior are characterized and compared. The results reveal that a small amount of Zn doping (2at.%) is highly beneficial for the performance of LiMnPO4 due to the reduced charge transfer resistance, the increased lithium ion diffusion and phase conversion, but this effect is remarkably traded off at a high level of Zn doping (10at.%). Compared with LiMnPO4, LiMn0.98Zn0.02PO4 has a much higher capacity and a much better rate capability. After 2at.% Zn doping, the discharge capacity increases from 101 to 139mAhg−1 at 0.1C and 56 to 105mAhg−1 at 2C.