"Too Busy Thinking About My Baby" was Gaye's second biggest hit of the 1960s, after "I Heard It Through the Grapevine". "Too Busy Thinking About My Baby" peaked at number four on the Billboard Hot 100 in the United States, and remained at the number one position on Billboard's Black Singles Chart for six consecutive weeks, from the weeks of, June 7 until July 12, 1969 with sales totaling 1.5 million copies The single was the top selling R&B single of the year and was the first release from Gaye's 1969 studio album M.P.G..