Yiallouros was born in Rizokarpaso, Ammochostos province, on August 29, 1938. He attended the Greek High School of Ammochostos where, during the EOKA struggle against the British, he became responsible for passing propaganda leaflets and organising his fellow students.
On February 6, 1956, following an altercation between students and British troops, the colonial authorities shut down the high school. On the next day, February 7, 1956, the students organised a protest. Yiallouros led them as flag-bearer. When the students started throwing rocks at the troops, they answered with live ammunition and killed Yiallouros. His last words were: "Long live Enosis!"