Calcium vanadate nanorods with Ca10V6O25 phase have been synthesized by a hydrothermal process without any surfactants. Hydrothermal temperature, reaction time and calcium (Ca) raw materials play important roles in the formation and size of the calcium vanadate nanorods. The nucleation and crystal growth combined with crystal splitting process have been proposed to explain the formation and growth of calcium vanadate nanorods. The calcium vanadate nanorods are used as glassy carbon electrode-modified materials to analyze the electrochemical behaviors of tartaric acid. The calcium vanadate nanorod-modified glassy carbon electrode exhibits good performance for the electrochemical detection of tartaric acid with a detection limit of 2.4 μM and linear range of 0.005–2 mM. The analytical performance and straightforward fabrication method make the calcium vanadate nanorods promising for the development of electrochemical sensors for tartaric acid.