[2] Prior to his secondment to the United Nations, he worked for Peru's foreign ministry in Lima and at its UN missions in New York City and Geneva.
Following his appointment as the Secretary-General's Personal Representative for the Central American Peace Process, Ambassador de Soto headed the 1990–1991 negotiations that brought an end to the decade-long civil war in El Salvador.
On 1 November 1999 de Soto was selected as the Secretary-General's Special Adviser on Cyprus, with the rank of Under-Secretary-General; he held this post until the dismantling of the Special Mission to Cyprus following the April 2004 rejection of the Annan Plan for a Cypriot bizonal bicommunal federation divided along ethnic and religious lines.
He wrote a 53-page End of Mission statement, dated 5 May, "meant only for senior UN officials", with "wording far more critical than the public pronouncements of UN diplomats".
[3] [4] Álvaro de Soto is a Member of the Global Leadership Foundation, an organization which works to support democratic leadership, prevent and resolve conflict through mediation and promote good governance in the form of democratic institutions, open markets, human rights and the rule of law.