In 1973 and 1974, he represented his country in the Security Council, serving as its president at the time of the events in Cyprus in July 1974. On 18 September 1975, he was appointed Special Representative of the Secretary-General in Cyprus, a post he held until December 1977, when he rejoined the Peruvian Foreign Service. During his time in Cyprus, Perez de Cuellar married his second wife, the former Marcela Temple Seminario.