The song peaked at the top of the Billboard Hot 100, and became the best-selling single of 1967 in the United States.

At the time, it made Lulu only the second British female artist to top the US charts during the listing's Rock era after Petula Clark's "Downtown" in 1965—and third in the overall history of the US charts after "Downtown" and Vera Lynn's "Auf Wiederseh'n Sweetheart" in 1952—and so far the first of two Scottish female solo artists to achieve the feat.

For 44 years, Lulu and Easton were the only Scottish solo artists to have topped the Billboard Hot 100—a record that ended when Calvin Harris topped the chart alongside Rihanna on their collaboration "We Found Love" in November 2011.

The film's director, James Clavell and Lulu's manager Marion Massey were angered and disappointed when the title song was not included in the nominations for the Academy Award for Best Original Song at the 40th Academy Awards in 1968.

[2] "To Sir With Love" was initially recorded by Lulu (with The Mindbenders, who also acted in the film).