While the Nitish Kumar-led government claimed millions took part in the event, the opposition led by the Rashtriya Janata Dal (RJD) termed it a waste of time, money and effort.
Addressing the media, Bihar Chief Secretary Deepak Kumar said 57,76,788 people formed the 18,034 km human chain and made a world record of the longest human chain.
Chief Minister Nitish Kumar, Deputy Chief Minister Sushil Kumar Modi, environmentalist Rajendra Singh, several Ministers and officials participated in the event.
According to reports, two participants Mohammad Dawood a teacher in Darbhanga and Reshma a resident of Samastipur died due to heart attack while taking part in the event.
The Chief Minister said the human chain was formed to send across the message about the importance of environment and create awareness about it. Thanking the people for making the event a grand success, he said, "We will continue to organise such campaigns."
The Opposition alleged that Kumar misused the official machinery and resources to give a boost to his image ahead of the Assembly elections, likely in the second half of the year.
"The way schoolchildren were asked to form the human chain and stand in the cold weather exposes the Chief Minister's nervousness. Several school children fell ill during the event," said RJD leader Tejashvi Yadav.
While the Chief Minister didn't visit flood-hit areas because of non-availability of helicopter, his government had deployed 15 choppers to film the event, Yadav said.
It was an attempt to divert people's attention from increasing crime and unemployment in the state, said another opposition leader.
( With inputs from IANS )