Malcolm's career began with journalism when he was drafted during the Korean War and was assigned to work on the Pacific edition of 'the Stars and the Stripes' for two years. For some time he worked for the Middletown Times Herald-Record then worked at the Associated Press, in which he was eventually appointed as the chief correspondent for Indochina.
June 11, 1963 began the photo aspect of his career. Taking renown photos of the death of Thích Quảng Đức he received a Pulitzer Prize for International Reporting and was offered a multitudes of job opportunities. In 1965 he left the Associated Press. For about a year he worked in the television journalism field at ABC TV, but eventually he became dissatisfied with the occupation and for several years he worked freelance.
For a year Browne did fellowship at the Columbia University with the Council on Foreign Relations, and in 1968, he joined The New York Times, and a mere four years late, in 1972, he became its correspondent for South America. But before becoming a journalist Browne worked as a chemist, and in 1977, he became a science writer, in which he served as a senior editor for Discover. In 1985 he returned to The New York Times, and in 1991, he covered the Persian Gulf War.