A military statement identified the missile as the Pakistan-developed Hatf-2 Abdali, and said it is capable of hitting targets within a range of 200 kilometers.
Officials said neighboring nuclear-armed rival India had been given prior notification about the launch.
The test came Pakistani President General Pervez Musharraf was due today to open a visit to China, one of Pakistan's main weapons suppliers.
It also came as French President Jacques Chirac was opening a visit to India to discuss possible civilian nuclear technology cooperation between France and India.
(compiled from agency reports)
DECLARED NUCLEAR-WEAPONS COUNTRIES:
country warheads (est.) date of first test
United States 10,500 1945
Russia 18,000 1949
United Kingdom 200 1952
France 350 1960
China 400 1964
India 60-90 1974
Pakistan 28-48 1998
North Korea 0-18 2006
Israel is widely believed to possess nuclear weapons, but it has not declared itself a nuclear-armed country.
South Africa constructed six uranium bombs but voluntarily dismantled them.
Belarus, Kazakhstan, and Ukraine all gave up the nuclear weapons that were on their territory when the Soviet Union collapsed in 1991.