He was born in Jagüey Grande, Province of Matanzas, on October 18, 1936. He graduated with a Bachelor of Science and Letters in 1955 and, after a year of university studies, he entered the San Alberto Magno Diocesan Seminary, governed by the Fathers of The Foreign Missions of Quebec, in the year 1956. After the first four years of studies in humanities and philosophy, he was sent by his bishop to the Foreign Missions Seminar in Montreal, Canada, where he studied theology.

He returned to Cuba and was ordained a priest on August 2, 1964 in the Cathedral of Matanzas. Vicar Cooperator in Cárdenas until 1966. In 1967 he was appointed parish priest of Jagüey Grande, his native town. Like all parish priests in Cuba, during this period of scarcity of priests, Fr. Jaime Ortega attended several parishes and churches simultaneously.

In 1969 he was appointed parish priest in the Cathedral of Matanzas, attending both the parish of Pueblo Nuevo, in the city, and two other churches in the countryside. He was at the same time president of the Diocesan Commission of Catechesis and made an active apostolate with the young people of the diocese. In those years, even more difficult for the pastoral action of the Church, he initiated in the diocese a youth movement that included other forms of apostolate, summer camps for young people and an evangelizing work through plays, represented by the very young.

For several years, together with his pastoral activity in the city of Matanzas, he taught at the San Carlos and San Ambrosio Inter-diocesan Seminary in Havana, where he traveled every week to teach Moral Theology courses.