Lagomarsino made several trips abroad as a congressman. He toured South America, the Far East, the Pacific Region, the Soviet Union, and Europe numerous times, but held a particular interest in Southeast Asia; meeting with the Laos government in 1989 and, later, the Vietnamese government in 1990, to obtain information on American POW/MIA's in Southeast Asia. He toured the Panama Canal as part of President Carter’s diplomacy and was an observer to the Panama's national elections and Kuwait invasion under President Bush. Lagomarsino also attended annual interparliamentary conferences held in Mexico and on the European continent.