Meroni, of Romani heritage, began playing football in a small courtyard of 60 square metres, and then moved to the field of the Oratorio di San Bartolomeo in Como.

His mother Rosa, a professional weaver, had financial difficulties raising three children: Celestino, Luigi (called Luigino, then Gigi) and Maria.

[1] Rumors of his move to cross-city rivals Juventus, for an offer of 750 million lire, triggered a sort of "crisis" and then popular Torino president Orfeo Pianelli, under the pressure of the fans, declined.

[4] He participated in the ill-fated expedition led by coach Edmondo Fabbri at the World Cup in England in 1966, which culminated with the incredible 1–0 defeat to North Korea, and Italy's elimination in the first round.

A diminutive, elegant, and highly talented player, with a slender build, who was regarded as one Italy's most promising wingers, his biggest strength was his excellent and unpredictable dribbling ability, which allowed him to trick and beat opposing defenders with feints.

Shortly after the end of a 4–2 victory over Sampdoria, in which he was sent off, Meroni was hit by a motorist while recklessly crossing Corso Re Umberto in Turin with his friend and Torino teammate Fabrizio Poletti.