"Mah Nà Mah Nà" was a hit in many countries in 1968–1969. In the U.S., it peaked at #55 in the "Billboard" Hot 100 singles chart and #44 on the "Cash Box" magazine chart in October 1969. It also reached #12 on the U.S. Adult Contemporary chart. In Canada the song reached #22 in the RPM Magazine charts. The UK single release, on the Major Minor label, was credited to "The Great Unknowns", and featured Giorgio Moroder's "Doo-be-doo-be-do" on the B side (also sometimes featured in "The Benny Hill Show"). Umiliani's own version reached number 8 in the UK in 1977. During its 1–15 September 1969 run on the WLS 890 Hit Parade, the surveys erroneously credited the record to someone named Pete Howard. WPTR did much the same, except that the erroneous credit went to someone named J.W. Wagner.