Trivia

When Mayra Gomez-Kemp became the host of the show in 1982, she became also the first woman in the world to host a prime time TV game show alone without the company of any man.

In spite of the fact that it was nearly impossible to leave the show without earning at least 25 pesetas, thanks to the rules of counting as one answer the example the host gave after a question, which could be repeated by the contestants, in 1976 there was a couple that finished with 0, because they didn't repeat the example and so 25x0 was 0. This way, no matter how many answers they performed in the following questions, as each answer was 0 pesetas, they finished with 0. It never happened again.

Hundreds of episodes from the seventies and early-'80s were destroyed due to TVE's policy of erasing archive tapes to re-use them and save money, a practice that was maintained, in the case of "Un, dos, tres", until 1986.

From the first season, which had 54 episodes, only three of them, El terror (1972), El mundo de los toros (1973) and El circo (1973) have survived the wiping in their complete form. From the second season, which had 83 episodes, only four have survived in their complete form, Las mil y una noches (1976), Las zarzuelas (1976), La piratería (1976) and El mundo infantil (1977). 30 out of 84 episodes survive from the third season, and only 4 out of 26 from the fourth season.

The fifth season is when the purge was stopped, with the first 14 episodes from that season being erased. From the 15th episode of the fifth season onward, all the episodes remain intact in the archives. Apart from that, fragments of other episodes have been found, the oldest one a fragment containing the final 12 minutes from Episode #1.4 (1972), and there are also some tapes containing raw fragments from the original making of some lost episodes as well as some known VHS, Betamax or Video 2000 recordings of lost episodes in the hands of private individuals.

In March 2019, TVE ended publishing in their official web page all the episodes they keep in their archive vaults. Only 185 episodes out of the 413 that were made have been published.

In 1982, Narciso Ibañez Serrador had chosen the then trio Martes y 13 (composed at that time by Josema Yuste, Millán Salcedo and Fernando Conde) to be the new negative part. But in the end, the roles went to Paloma, Teresa and Fernanda Hurtado, who eventually stayed for seven consecutive seasons in the cast.

This was the very first Spanish show to be exported to different countries. United Kingdom had 3-2-1 (1978) , Portugal had 1, 2, 3 (1984), Germany had Die verflixte 7 (1984), the Netherlands had "De 1-2-3 Show" (1976) and Belgium also had their own version. Until before the arrival of Operación triunfo (2001), no other Spanish show repeated this international success.