The service was launched by the Bangladesh road transport minister Obaidul Quader at the Bangladesh Road Transport Corporation (BRTC) bus depot on Friday with an aim to promote people-to-people contact, bdnews24.com reported.
A 26-seater BRTC bus left for Guwahati with 22 government officials on Friday.
Rundown roads were identified as major trouble during a trial run on the route from Guwahati in December last year.
Quader said the road condition was not good and that the hilly Shillong-Dauki-Tamabil road was full off turns and quite risky.
"The drivers must take great caution on this road. We've taken initiatives to provide necessary training to Bangladeshi drivers," the minister added.
Keeping Dhaka-Guwahati road width in view, buses longer than 12 metres will not be allowed to ply on the route.
"The BRTC has finished preparations for this," said the minister.
The bus service is likely to be formally flagged off during Indian Prime Minister Narendra Modi's expected visit next month.
He said an agreement and a protocol had to be signed between the two countries before the services were introduced.
"The paper work for the agreement and protocol will be done this month and we hope they will be signed during the Indian prime minister's possible visit next month," he added.