Brudnoy began a career in broadcast commentary in 1971 on Boston's local PBS television station, WGBH-TV. In 1976, he took over as host of his friend Avi Nelson's radio show on WHDH, in the midst of the city's unrest over forced busing and desegregation in schools. He took to the job with ease, and increasingly gained popularity. From 1981 to 1986, he appeared on former Top 40 station WRKO, which was now news and talk, before moving to local stalwart WBZ. The top-rated talk radio host in New England, he appeared in a regular weekday evening slot until his retirement. At the end of his career, Brudnoy was, according to WBZ Radio's promotional materials, derived from Arbitron ratings, among the most-listened-to evening talk hosts in the United States.