The leftist Chavez received 62 percent of the vote, according to Venezuelan electoral officials. Rosales, a free-market advocate critical of the Chavez's socialist policies, conceded defeat, Globovision reported Monday.
The outspoken Chavez, an ardent critic of the Bush administration called his victory "another defeat for the North American empire."
Chavez gained popularity by funding broad social welfare programs on the country's oil revenue and campaigned on the platform that his opponent was a puppet of the United States.
Rosales is governor of the western oil-rich state of Zulia, and during the campaign said Chavez was turning the country into a communist state while squandering Venezuela's oil wealth and called him "a puppet seated on (Cuban leader Fidel) Castro's lap."