Bro Kilian entered the Hospitaller Order of St. John of God, Dublin in 1946. From there he studied at UCD in General Nursing and Psychiatric Nursing between 1966-1972 and began his training in St.Vincent's Hospital at the time he was the only male student. Bro Kilian also holds a Master’s Degree in Hospital and Public Health Administration at University College of Dublin. In 1980 he was appointed Director of St. John of God Psychiatric Hospital, Stillorgan, Dublin, for 8 years.

In 1989 Bro Kilian moved to Korea to become Director of Capital & Property Development of St. John of God Services, Korea &
Director of Fundraising Office, Korea. Moving back to Dublin in 1998 to work with the Research and Development Institute of Hospitality in 2000 becoming the Director of the Institute until 2010. Presently Bro Kilian is a member of Institute of Hospitality and St. John of God Hospital  Local Hospitality Team, Dublin.