The rocket was launched at 7.35 p.m. local time (22:35 GMT), delivering two satellites, HOT BIRD TM-9 and W2M, into orbit.
"This was the 42nd launch of an Ariane 5 and the 28th successful launch in a row," Arianspace SA said.
HOT BIRD TM-9, built by Astrium as the prime contractor, is designed to transmit television programs to cable and satellite households in Europe, the Middle East and North Africa, Arianspace SA said.
The W2M satellite, built by a consortium comprising Astrium and the Indian Space Research Organization (ISRO), will allow Eutelsat to offer a wide range of services, including TV broadcasting, data network feeds and broadband access, Arianspace SA said.
In addition to fixed-beam coverage of Europe, North Africa and the Middle East, the W2M satellite will include a steerable beam for coverage of islands in the Indian Ocean, Arianspace SA said.
Kourou is located 50 km (31 miles) from the town of Cayenne on the Atlantic coast of South America.
The European Space Agency launch facility is mainly used to launch geostationary satellites into orbit. The first launch of a Russian Soyuz-ST rocket from Kourou is due in late 2009.
The center's proximity to the equator will allow the modernized Russian rocket to orbit heavier satellites than from the Baikonur space center in Kazakhstan and Plesetsk in northern Russia.