The Como version would be one of his most influential records, and in February 1971 it became his first song to reach the top ten of the Billboard Hot 100 in more than 12 years, peaking at #10. The song's peak on the Hot 100 chart came just weeks after concluding a four-week run at number one on the BillboardEasy Listening chart. On the UK Singles Chart, the single reached #4 in 1971.
Elvis Presley recorded "It's Impossible" on stage at the Las Vegas Hilton February 16, 1972. This version was released on his 1973 album, "Elvis."
In 1976 the song was arranged by Soviet composer Georgy Firtich as the gangster song for the cartoon series Adventures of Captain Wrongel that became the most famous tune from the series. Firtich, rather than Manzanero, is still credited as the composer.
Andrea Bocelli has covered the song as a duet with Christina Aguilera, Katharine McPhee and Rimi Natsukawa in 2006. Aguilera features on Bocelli's album, Amore, with the duet with Natsukawa is a bonus track of the album's release in Japan. The duet with Natsukawa also appears as a bonus track for the Japanese version of Bocelli's The Best of Andrea Bocelli: Vivere. McPhee joined Bocelli onstage at the JCPenney Jam and their version is included on the album for the event.
Luis Miguel recorded another version on his album, Segundo Romance, which was co-produced by Manzanero. Manzanero himself recorded the song as a duet with Puerto Rican singer Olga Tañón for his 2001 album Duetos.