Chavez on Monday called the 12-page report that was delivered to the U.S. Congress last week "a disgrace," saying "these are the things they raise and repeat in reports to later justify anything."
In the report, the Pentagon concluded that Iran's Qods Force, an elite unit within its Islamic Revolutionary Guard Corps, is well established and increasing its presence in Latin America, particularly Venezuela.
"It's totally false," Chavez said of the report's findings.
The unclassified Pentagon report did not include more details on what an increased presence by the Qods Force might entail. Pentagon officials have separately said that they do not believe Iranian terrorist proxies in Venezuela pose a threat to the United States.
Since taking office in 1999, Chavez has strengthened ties with Iran. The two countries have signed a wide range of cooperation agreements including the construction of an auto-assembly plant and agriculture projects in Venezuela.
But the two increasingly close allies have not publicly signed any deals regarding military cooperation.
During a trip to South America earlier this month, Defense Secretary Robert Gates played down any potential military threat Iran might pose in the Western Hemisphere.
"I haven't seen much evidence of that in Latin America, in terms of Iran having proxies or terrorist proxies," Gates said.
On Venezuela's hostility in particular, Gates said: "I certainly don't see Venezuela at this point as a military challenge or threat."
The Pentagon report was intended as a snapshot of Iran's military power and the threat it poses to the U.S. and deployed American troops.
Meanwhile, a day after saying he hopes to eventually cool tensions with Colombia, Chavez charged that his neighbor recently allowed a U.S. military plane to carry out "electronic warfare" operations against Venezuela.
Chavez told a crowd of soldiers Monday that his intelligence services detected the American aircraft that he said took off from a Colombian base and flew along the border between the two South American nations, which have seen long tense relations worsen in recent months.
Without giving details, he said Venezuela's military intelligence intercepted a conversation between the pilot and air traffic controllers in the northern Colombian city of Barranquilla.
The aircraft conducted espionage operations, he said.
"Through our strategic intelligence, we detected an RC-12 airplane belonging to the U.S. Air Force," Chavez said during a talk to an auditorium packed with military officers, rank-and-file soldiers and cadets.
"It was a plane specialized for electronic war, and it was carrying out electronic war operations," he added.
U.S. Embassy spokeswoman Robin Holzhauer would not directly respond to Chavez's accusation during a telephone interview on Monday, saying only that "the United States and Colombia engage in a number of bilateral activities," all of which "respect the sovereignty of other nations."