“The first respondent (Mahama) was validly elected and the petition is therefore dismissed,” presiding judge William Atuguba said, reading from the verdict issued by the nine-judge panel.
The sometimes tense proceedings had been broadcast live on radio and television and were followed closely across the nation of 25 million people.
In the December polls, Ghana’s electoral commission said Mahama took 50.7 percent of the vote over NPP candidate Nana Akufo-Addo’s 47.7 percent.
Observers called the vote fair.
But the NPP levelled an array of allegations, including that tally sheets had been doctored and ballot boxes stuffed, among other irregularities.
Some of the judges found merit in some of the NPPs allegations but as a group they declared Mahama’s win legitimate.