In spite of his fame as a portraitist in his own day, only one signed portrait by Maíno has survived: the Portrait of a Gentleman in the Museo del Prado. This is a work of outstanding quality in which the artist used pictorial formulas developed by El Greco in Toledo while also taking account of contemporary northern European painting. In 1935 the Portrait of a Monk in the Ashmolean Museum was attributed to Maíno and can probably be considered a self-portrait on account of its intensely introspective mood. As a portraitist, Maíno has been compared to Velázquez, Zurbarán, Alonso Cano, Rembrandt and Rubens, among others.