He entered the Order of Friars Minor in the 1960s in Guizeh and began his novitiate on 30 September 1968 before making his simple profession on 1 October 1969.
Following his ordination he continued with additional studies from 1973 to 1975 at the Jesuit-run Saint Joseph University in Beirut in Lebanon where he obtained a licentiate in dogmatic theology in 1975.
Pope Benedict XVI appointed Zaky on 1 September 2009 as the Apostolic Vicar of Alexandria and also made him the Titular Bishop of Flumenzer;[2] he received his episcopal consecration on 31 October 2009 from Archbishop Michael Louis Fitzgerald, with Archbishop Marco Dino Brogi and Bishop Giovanni Innocenzo Martinelli serving as the principal co-consecrators.
[2] On 10 February 2014 the bishop met with representatives of various Christian communities in Our Lady of Heliopolis in Cairo to pray for peace and national stability.
Zaky said: "at the moment the common prayer of Egyptian Christians takes on a particular character: we are going through a time where severe episodes of violence continues in the country, but also one can see signs of hope on the horizon".