[1] Born in the city of San Miguel de Tucuman on 26 July 1862, Lillo was related to Lastenia Blanco, and journalist, Emilio J. Schleh.

He went to the National University of Córdoba for guidance from Federico Kurtz and the brothers, Oscar and Adolfo Döring and from whom he gained an appreciation of classification.

Shortly after he was appointed assistant and student of Friedrich Schickendantz, chemist and director of the Municipal Chemical office of Tucumán; a post to which Lillo succeeded in 1892.

He was appointed director of the Museum of Natural History at the University of Tucumán and member of the National Commission of Argentina flora.

Miguel Lillo was an amateur naturalist: extremely shrewd and observant; erudite and gifted with an extraordinary scientific vocation.