During his tenure there were some peasant uprisings and guerrilla outbreaks in Andean areas affected by poverty and oppression of the landlords and quickly suppressed with the help of the army.

This was an embarrassing lawsuit for the nation and unresolved several decades, was that the American International Petroleum Company, that had been illegally exploiting the oilfields of La Brea and Pariñas, located in the north of Peru, without providing the amount owed to the Treasury, which had been accumulating over the years.

Belaúnde sent Congress a bill to declare null the Agreement and Award Paris Convention (signed in time Augusto B. Leguia and favoring IPC) and requested that the fields of La Brea and Pariñas pass to Power of Attorney Oil Company (government agency).

On August 13, it was signed on Act of Talara by which all oil fields passed into the hands of the Fiscal Petroleum Company (EPF), while retaining the refinery, the distribution system and fuel national Concessions calls Lima.

That was the famous "Page 11" that would serve as a pretext for a group of army officers to give a coup less than a month later, accusing the government of "betrayal".

He was overthrown by a group of socialist-leaning military, led by General Juan Velasco Alvarado, at the time President of the Joint Command of the Armed Forces of Peru.

The army broke the gates and entered the Government Palace, then a group of soldiers under Commander Enrique Gallegos arrived at the rooms and they drove Belaúnde to a truck that brought him to the Armored Division Headquarters.

Meanwhile at the airport was ready to leave a plane that the military rebels had prepared to escape on it in case the coup failed, or deport President Belaúnde if triumphed.