Authorities at the Shaheed Mukunda Kakoti Hospital here said the peasant leader had been released as he had recovered.
Gogoi had earlier said that he wished to be in the hospital till the time all the six accused named by him were arrested.
The Team Anna member blamed the government of turning "a blind eye to the plight of the common people" who had lost their homes in the ongoing flood.
Meanwhile, official sources said the leader is being taken to Guwahati under tight security. A police contingent is accompanying the RTI activist, who is also the general secretary of Krishak Mukti Sangram Samiti.
Gogoi was attacked by some miscreants while he had gone to visit flood-hit areas in Punni village under Dharampur Assembly constituency, represented by Assam Agriculture Minister Nilamoni Sen Deka.
