From 1960 to 1980 she was head of the Child Psychotherapy service at the Tavistock Clinic, taking over from Esther Bick, who had established a foundational method of disciplined infant observation.
Harris was responsible for the subsequent expansion in the number of English and international trainees at the Tavistock, and for laterally developing the training into what became known as the Tavi Model.
[17] In 1976 at the request of the Organisation for Economic Co-operation and Development they collaborated on A Psychoanalytical Model of the Child-in-the-Family-in-the-Community, written for multidisciplinary use in schools and therapeutic units.
[18] In the late 1970s Martha Harris invited Wilfred Bion back to London from California to give a series of lectures at the Tavistock.
[21] Martha Harris wrote newspaper articles and books for parents on child development, in addition to many papers on psychoanalytic training and clinical work.