Chavez also received the sacrament of the Anointing of the Sick.
"It's the Anointing of the Sick, formerly called extreme unction," Monsignor Mario Moronta said. "There's no need to be afraid, this is so that the sick person may have physical strength, but above all spiritual. This requires spiritual preparation and it is given to those who have received that preparation."
The Cabinet and armed forces brass accompanied Chavez during Tuesday's service at the Military Academy in Caracas, which was broadcast on state television.
During the service, the president approached Moronta, who anointed him on the forehead with "holy oils."
The monsignor asked God to preserve the "spiritual and corporal health" Chavez needs to continue to carry out his duties and he also prayed that "this situation he has experienced" will help him "in his process of purification."
Chavez was called upon to perform the first reading during the Mass, a psalm of Saint James.
"I clothe myself in humility and from the depths of my heart and my soul emerges the altar boy that I was and the altar boy who I continue to be deep inside," said the president before beginning the reading.
"We ask you, Lord, for the health of everyone, for physical and spiritual health, for the health of the Bolivarian fatherland," said Chavez after reading the passage.
The Venezuelan leader has maintained a tense relationship with the Catholic Church during his tenure in office, and he has claimed that some bishops have involved themselves in politics.
The 56-year-old Chavez complained of abdominal pain during an official visit to Cuba early last month, and emergency surgery to remove an abscess led to the discovery of cancer.
The president has not disclosed exactly what kind of cancer he has.