Once a close associate of Chief Minister Tarun Gogoi, Sarma had resigned from his ministry last year following differences.
Accompanied by state BJP President Siddhartha Bhattacharjee, Sarma called on the BJP national president at his residence in New Delhi.
The rebel Congress leader said he expressed his desire to join BJP and work under the leadership of Prime Minister Narendra Modi and party president Amit Shah. He also discussed Assam's political and flood situation.
Bhattacharjee also announced that Sarma would join the party and the final formalities would be worked out at the state level.
Sarma's differences with Gogoi came to the fore following the 2011 Assembly polls. Claiming the support of more than 30 MLAs, he had urged the Congress high command to remove Gogoi as Chief Minister.
The former Education and Health Minister of Assam was questioned by the Central Bureau of Investigation in connection with the multi-crore Saradha chit fund scam in November last year.
Sarma held the Guwahati Development Department portfolio when Louis Berger was selected as consultant for the Guwahati Water Supply project, being implemented by the GMDA with funds received under the Japan International Cooperation Scheme.
Asked if he was assured of any post in BJP, Sarma today said that he had only decided to join the party and has not bargained for any post.
On whether other dissident Congress legislators could follow suit, the former Minister said that he was not in a position to say anything on behalf of others.