Many past and present teammates of the five-time Ballon d'Or winner are in attendance at the the ceremony.
Some of the guests who attended the occasion include Luis Suárez, Neymar, Gerard Piqué, ex Barca team mates, Carles Puyol, Xavi Hernandez and Samuel Eto'o at an event held in Rosario, Argentina.
The union, which was nothing short of glamour saw an Argentine newspaper, Clarin aptly describe it as "the wedding of the century".
Messi and his wife who already have two children, Thiago and Mateo, met when they were children and had kept the connection even after he moved to Spain at the age of 13.
Roccuzzo is reported to be the cousin of the Barcelona forward's best friend, Lucas Scaglia, who plays as a midfielder for Jacksonville Armada in the North American Soccer League.
To accommodate some of his 260 guests, the five-time Ballon d'Or winner hired the City Center Rosario complex which had the Pullman Hotel where the cheapest lodging is put at almost £100.
No surprise there for an occasion of such huge importance which has had the whole of Argentina on stand-still.