Margarita Comas Camps (1892-1972) is possibly the most important Spanish woman scientist of the first third of the 20th century. A researcher and teacher who did a great deal for science, education and feminism, she was an excellent teacher who knew how to combine a solid scientific background (in the form of her PhD in Science) with an unequivocal concern for educational issues. She was an activist of the New School movement and a committed Republican. In 1932, Margarita Comas joined the Seminar of Pedagogy of the Faculty of Philosophy of the University of Barcelona as a professor of Child Biology. Like most of her fellow teachers, she went into exile to help the children who took refuge in England from the calamities of the Civil War. This article describes this interesting figure, first via a biographical outline and then an analysis of her scientific and pedagogical achievements