Rejecting a Movement for Democratic Change application to force the electoral commission to release the result, Judge Tendai Uchena said: "I dismiss the case with costs."
The MDC says its leader, Morgan Tsvangirai, defeated President Robert Mugabe in the vote, ending his 28-year rule.
The MDC went to the High Court after a long delay in issuing the result by the Zimbabwe Electoral Commission (ZEC).
Judge Uchena did not explain his judgement, but said the court would make it available by tomorrow.
The ZEC opposed the MDC's application and says it is still counting and verifying the votes.
Zimbabwe's economy is in ruins, with the world's worst rate of hyper-inflation, but the judgement appeared to delay even further the time when the population will find out whether Mugabe's almost three decades in power are over.
The opposition says Mugabe is holding back the presidential result to allow him time to prepare a violent response to his biggest electoral setback, when the ruling ZANU-PF party lost control of parliament in a parallel vote on March 29.
MDC spokesman Nelson Chamisa told Reuters: "Naturally we are very disappointed because I think we have a very strong case. We are going to decide the way forward after meeting our lawyers, but in our view the release of those results is very, very urgent."
MDC lawyers said they would decide whether to appeal after studying the High Court judgement. The opposition has called an indefinite general strike for Tuesday to protest against the delay.
Southern African leaders said after a summit in Lusaka at the weekend that the election result should be released "expeditiously".
Further delays are expected because of legal manoeuvres and a recount of 23 constituencies ordered by the ZEC for next Saturday. The MDC is also challenging that decision in court.
ZANU-PF says neither Tsvangirai nor Mugabe won the necessary absolute majority in the presidential vote and a run-off will be necessary.
The delays have stoked tension in the southern African nation and brought a chorus of Western condemnation.
Both MDC and international human rights organisations say Mugabe has unleashed militias in a campaign of violence to intimidate opposition supporters ahead of a runoff.
The MDC says hundreds of villagers have been forced out of their homes by militia attacks and at least 50 needed medical treatment.
A quarter of Zimbabwe's population has fled to escape inflation of more than 100,000 percent, chronic shortages of food and fuel and 80 percent unemployment.
The ZEC's recounts could overturn the MDC's victory in the parliamentary vote, Mugabe's first defeat since taking power after independence from Britain in 1980.
MDC lawyer Selby Hwacha accused the ZEC of calling the recount to help ZANU-PF rig the poll.
In what the opposition says is a propaganda campaign, state media on Monday published a document alleged to have been written by MDC Secretary-General Tendai Biti containing the party's plans to bribe polling officials to inflate MDC votes.
"This is a dirty campaign, a sign of desperation, publishing false documents which they have authored themselves," the MDC's Chamisa said.
Tsvangirai, who says he is a target of security forces, has said widespread violence could erupt unless African states intervene.
The summit of SADC (Southern African Development Community) in Lusaka at the weekend urged Mugabe to ensure any run-off would be held "in a secure environment".
The former guerrilla commander did not attend.
Zimbabwe's neighbours, particularly regional power South Africa, have been flooded with millions of economic refugees, causing outbursts of xenophobic violence.