June Walker, who died yesterday at 74, was chairwoman of the Conference of Presidents of Major American Jewish Organizations, and an activist national president of Hadassah, where she spearheaded the women’s Zionist organization’s advocacy of stem-cell research and support of medical institutions in Israel.

Walker was a respiratory therapist who taught for many years at Passaic Community College in New Jersey and was a director of education for pulmonary medicine at Columbia-Presbyterian Hospital in Manhattan. A lifelong involvement in women’s causes and Hadassah culminated in her election as Hadassah’s 23rd president in 2003.

As president, she brought increased visibility to Hadassah’s medical mission. She helped raise $75 million for a new tower at the organization’s hospital at Ein Kerem, Jerusalem.

She was a passionate advocate of women’s rights and medical practice. When in 2007 a group of 125 British physicians proposed expelling the Israel Medical Association from the World Medical Association on grounds that the IMA had failed to uphold international medical ethical standards in the Palestinian territories, she had Hadassah condemn the campaign as “unconscionable,” and added, “Israeli hospitals … unfailingly offer equal care and treatment to all who enter their doors without regard for race, religion, or political beliefs.”

Walker was born June 19, 1934, in the Bronx. Her father manufactured tobacco pouches for pipe smoker, and her mother was president of a local Hadassah chapter. Walker attended Hunter College High School and then Adelphi College, where she met her future husband when they were respectively president and vice president of the campus Hillel.

Walker worked as a medical research technician at Rockefeller University in the 1960s while raising a family. The Walkers lived in Rockaway, N.J., where her husband, Barret, was a mathematician working at Picatinny Arsenal.

Walker became president of her local Hadassah, and gradually got more involved in the organization’s national affairs. She chaired Hadassah’s American Affairs policy lobbying department, launched educational programs on the radical right and health care, and developed a textbook review program. She also campaigned for Rep. Barbara Boxer’s Violence Against Women Act and organized Hadassah’s participation in national marches on Washington for women’s rights. She served as national chair of the Hadassah College of Technology in Jerusalem, where enrollment grew to 2,200 students from 600 under her administration.

When she took office as president, she was quoted in an interview as saying, “Hadassah is the perfect synthesis of everything I am most interested in — Judaism, education, medicine, and Zionism.”

As chairperson of the Conference of Presidents starting in 2007, Walker helped bring together leaders of all facets of Jewish life in America. She was only the second woman to serve in the post.

In June, she was awarded an honorary doctorate from the University of Haifa for her work on Israeli health care. She attended the awards ceremony despite her illness. “It was the greatest moment of her life,” said her husband.

Expressions of grief were issued by the Israeli consul general and the World Jewish Congress, among others.

In addition to her husband, she is survived by two daughters, Ellen and Julie, and a son, David, and six grandchildren.