In July 1980 he was appointed Minister of Justice and Worship[2] by Fernando Belaunde Terry, as such a ministry had to refound disappeared in the Revolutionary Government of the Armed Forces remained in office until August 1981.
Inside the Senate, he was member of the Permanent Commission of the Congress and the Committees on National Defense and Justice and Internal Order.
In the 1990 general election, he was reelected as Senator representing his party under the FREDEMO coalition of Mario Vargas Llosa for the period 1990 to 1995.
[3][4] With the coup of 1992, Osterling was unable to perform his duties and was even beaten by the police that restricted entry to the Congress because he was under "house arrest".
Today is the study's lead attorney Osterling, Vice Chairman of Volcan Compania Minera.