Margot Zemach was born in Los Angeles, California and studied at the Los Angeles County Art Institute. She won a Fulbright Scholarship to study drawing in Vienna. In 1957, she married Harvey Fischtrom, a fellow Fulbright student with whom she had four children, and began a collaboration that produced 13 children's books before his death in 1974.
She created the drawings and he wrote the text under the byline of Margot and Harve Zemach. They also worked with their daughter Kaethe Zemach on a collection of stories called The Princess and the Froggie (1974). Ms. Zemach's own first book was an adaptation of the folktale The Three Sillies (1963). She became the illustrator or author of more than 40 children's books in total, and worked with other leading authors such as Isaac Bashevis Singer, Alvin Schwartz, and Randall Jarrell. She won the Caldecott Medal
in 1974 for Duffy and the Devil. She also wrote an autobiography, Self Portrait (1978). She died at age 57 of amyotrophic lateral sclerosis or Lou Gehrig's disease.