The Himalayan republic is home to eight of the world's 10 highest peaks and welcomes hundreds of adventurers each spring, when temperatures are warm and winds are typically calm.
The verdict was issued in late April but a summary was only published this week.
Lawyer Deepak Bikram Mishra, who had filed a petition urging permits to be curtailed, told AFP that the court had responded to public concerns about Nepal's mountains and its environment.
"It has ordered a limit to the number of climbers... and also given measures for waste management and preservation of the mountain's environment," Mishra said.
The verdict's summary said that the mountains' capacity "must be respected" and an appropriate maximum number of permits should be determined.
The full text of the verdict has not been published and the summary does not mention any specific limit to the number of permits issued.
Nepal currently grants permits to all who apply and are willing to pay $11,000 to scale Everest, the world's highest peak at 8,850 metres (29,035 feet) above sea level.
Last year, the country issued 478 permits for Everest, a record high.
A massive human traffic jam on Everest in 2019 forced teams to wait hours at the summit in freezing temperatures, risking depleted oxygen levels that can lead to sickness and exhaustion.
At least four of the 11 deaths on the peak that year were blamed on overcrowding.
'Give it some respite'
"We are pressuring the mountain too much and we need to give it some respite," Mishra said.
The court decision also orders restrictions on the use of helicopters for emergency rescues only.
Helicopters have in recent years been frequently used to airlift mountaineering teams to base camps and across hazardous terrain.
Nepal Mountaineering Association president Nima Nuru Sherpa said that such decisions need to be made after a proper study and consultation with the stakeholders.
"It is not clear right now how it will impact the industry. We don't know on what basis the limits will be made and how will this be divided among expedition operators," Sherpa said.
"Our focus should instead be on how we can make the mountains safer."
Nepal has issued permits to 945 climbers for its mountains so far this year, including 403 for Everest.
