Ananth Vishnu, an active worker of the Congress affiliated KSU, was found in a pool of blood with head injuries at Pulipparakkunnu around 7 pm yesterday.
He was rushed to a nearby hospital but declared brought dead, police said.
Vishnu, chairman of Ernakulam Government Law College Students Union, was riding his two-wheeler to his maternal home in Mattathur.
Congress MLAs, P T Thomas and Hybi Eden condoled Vishnu's demise.
Police said investigations were on to find out how Vishnu suffered the fatal head injury and an autopsy would be done in the government medical college hospital in Thrissur.