He taught Civil Law in the Faculty of Law at Santiago de Compostela University. He was a parliamentary deputy and was elected ministerial committee member for the exchange of war prisoners (Third Carlist War). From the professional point of view, he practised as a lawyer helping people in need and social outcasts. He founded San Vicente de Paúl Conference in Viveiro (Lugo).
On 1st January 1870, he published La lámapara del santuario.
In 1941, his remains were transferred to St Esteban Church in Zamora. In 1991, in the centenary of his death, his remains were transferred to Zamora's Cathedral. The process for his beatification started in 1994. Luis de Trelles founded the religious association 'Adoración Noctura Española' and inaugurated the Eucharistic Centre of Madrid in 1872. In the following years, he founded sections in Zaragoza, Valencia and several villages in the province of Valencia.