The Mission headed by a former Nigeria's vice president, Namadi Sambo, said the electoral process was peaceful and orderly.
Ghanaian voters came out in numbers on Saturday, 7 December to elect their new president and a 276-seat parliament under the Fourth Republic multi-party democracy from 1992.
At several polling stations visited by the Head of the ECOWAS Observation Mission, Namadi Sambo, in Greater Accra, which accounts for more than three million of the 18.8 million registered voters in the country, voters were in queues before the official opening of balloting at 7:00 am.
Only the ruling NPP and main opposition NDC had agents at the stations visited by the Head of the ECOWAS Mission. ECOWAS observers deployed to other regions reported similar situations.
Ninety-six-year-old Charles Owusu was among over 20 voters waiting to vote at the Flag Staff HSEJHs, Kanda polling station in the Ayawaso East Constituency, in Greater Accra. He said he had joined the queue by 6 a.m., while others said they arrived two hours before balloting opened.
When the ECOWAS Head of Mission and his team arrived at the station, which had 567 registered voters, polling staff and materials were ready, and one of the three police officers assigned to the station was also in place.
Voting started at exactly 7:00 a.m., with the first voter, Patience Yinne, 55, taking about five minutes to complete her voting process. A voter is processed to vote for the parliamentarian of their choice before returning to collect the ballot for the president.
On the premises of the 37 Military Hospital Officers Mess, which has four polling stations, and also at Ayawaso East, voting started at 7:20 a.m. in one of the stations with 470 registered voters.
Within the precinct of the Osu, Korle Klottey Constituency, the three polling stations were up and running, with 20 voters having cast their ballots in one station, out of the 671 registered voters when the ECOWAS head of Mission's delegation arrived around 7:50 am.
Voting officially ends at 5 p.m. before the sorting and counting of votes and declaration of results at the polling stations. This will be followed by results collation at the district, regional and national levels.
On his initial assessment, Mr Sambo, Nigeria's former Vice-president said the electoral process was peaceful and orderly.
More than 800 candidates are vying for parliamentary seats, while 12 candidates, including four independents, are seeking to replace outgoing President Nana Akufo-Addo of the ruling NPP.
It is a two-horse race between Mr Akufo-Addo's deputy, Vice President Mahamudu of the NPP and former President John Mahama the flag-bearer of the opposition NDC.
A candidate must score 50 per cent + 1 vote to win the presidency, otherwise, the two frontrunners will square up in a run-off vote, 21 days after the declaration of the first-round results.
Ghana's constitution stipulates that a new president must be sworn in on 7 January of an electoral cycle.
ECOWAS deployed more than 120 observers to observe the electoral process across the regions and districts.