Luis de Eguílaz was a disciple of the humanist and unfrocked friar Juan María Capitán. He found his dramatic vocation early; at age 14 he premiered the one-act comedy Por dinero baila el perro in Jerez de la Frontera. He studied law in Madrid and began his literary career with a critical study of the novel Clemencia by Fernán Caballero. He sometimes used the pseudonym El Licenciado Escribe (the graduate writer), a play on the name of the famous French dramatist Eugène Scribe.
In court he defended Eugenio de Ochoa, the man of letters and illegitimate son of
Sebastián Miñano . Thanks to him, Eguílaz was able to release his first serious work, Verdades amargas, in 1953, the success of which placed him among the most popular authors of the time. In the last years of his life he directed the National Historical Archive. He died on 22 July 1874 in his home on San Agustín Street in Madrid, and was buried in the
Cemetery of Saint Nicholas . The news greatly affected Marcelino Menéndez y Pelayo, who was spending that summer in Santander, and composed a poem in Eguílaz's memory dated 5 August 1874. There is an oil portrait of Luis de Eguílaz in the Ateneo de Sanlúcar de Barrameda.