Counting of votes for Madhya Pradesh Assembly's 230 seats began at 8 am Tuesday.
Exit polls predicted a close race between the BJP and the Congress, though leaders from both parties have routinely claimed their respective victories.
While Chouhan has called himself the "biggest surveyor" in claiming a win for the BJP, senior Congress leader Kamal Nath said his party would get at least 140 seats to oust the saffron party and form a majority government.
The state polls saw a voter turnout of about 75 per cent.
Madhya Pradesh Chief Electoral Officer V L Kantha Rao told reporters that counting began with the postal ballots at 51 centres across the state.
"EVMs (Electronic Voting Machines) would be taken up for counting at 8.30 am. Counting of postal ballots would continue simultaneously," he said.
Rao said 15,000 employees have been drafted for the counting process which will be monitored through 1200 CCTV cameras installed at 51 centres across the state.
The CEO said the maximum rounds of counting -- 32 in total -- would take place in the Indore-5 assembly segment due to the highest number of booths there.
The lowest number of counting rounds (15) would be held in Kotma seat in Anuppur district, he added.
Indore-5 seat is currently held by the BJP while the Congress represents Kotma constituency.
Rao said the results of every round would be declared separately before the start of the subsequent rounds.
Though all exit polls predicted a slide in the BJP's fortunes, some of them have gone to the extent of giving a clear majority to the Congress.
The Republic TV-Jan Ki Baat poll has predicted BJP will win 108-128 seats and the Congress 95-115. The India Today-Axis poll gave 102-120 seats to the ruling party and 104-122 to the Congress.
Times Now-CNX predicted a majority for the BJP with 126 seats and gave 89 to the Congress.
In contrast, the ABP News poll gave the Congress a decisive win with 126 seats and said the BJP would win 94 Assembly constituencies.
In 2013 elections, the BJP had won 165 of total 230 seats, followed by the Congress (58), BSP (4) and Independents 3.
The campaign for the polls was a high-decibel one with star campaigners like Prime Minister Narendra Modi and Congress chief Rahul Gandhi mounting vitriolic attacks in their respective speeches.
The prime minister had addressed ten public meetings across all regions of the state while BJP president Amit Shah held 26 public meetings and three road shows, said state BJP spokesman Rajnish Agrawal.
Rahul Gandhi addressed 22 public rallies and took part in about a dozen road shows.
The chief minister, in office since 2005, is seeking re-election from Budhni in Sehore district. He is pitted against Congress candidate Arun Yadav, a former minister.
Of the 5.04-crore registered voters, 3.78-crores (75.05 per cent) exercised their franchise.
The BJP fielded candidates for all 230 seats while the Congress fielded 229 nominees and left one seat (Jatara in Tikamgarh district) for its ally Loktantrik Janata Dal (LJD) of Sharad Yadav.
Mayawati-led Bahujan Samaj Party (BSP) fielded 227 candidates, while the Samajwadi Party (SP) contested 51 seats.
The Aam Aadmi Party (AAP) also fielded 208 candidates in its maiden elections in Madhya Pradesh, while 1,094 candidates contested as independents.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)