Andres Iniesta, Ludovic Giuly, Carles Puyol, Samuel Eto’o and Ronaldinho all put themselves on the scoresheet as the Catalan club ran riot.
"I'm very happy that we won in such a fashion. It's always good to make a winning start to the Champions League, especially at home," said Barcelona coach Frank Rijkaard.
"The first thing was to get the win, in the Champions League you have to respect every opponent. After that, yes, it was satisfying to score so many goals," remarked the club's captain Puyol, after their biggest win in a Champions League opening match.
In the other Group A match Londoners Chelsea prevailed 2-0 at home against German club Werder Bremen.
Ghanaian midfielder Michael Essien gave Chelsea the lead after 24 minutes when he pounced on a slip from Werder defender Petri Pasanen and finished clinically.
The visitors were unlucky not to equalise when Germany striker Miroslav Klose muscled his way past Khalid Boulahrouz and despite having Petr Cech well beaten his effort was denied by the cross bar.
On 68 minutes Greek referee Kyros Vassaras handed Chelsea a dubious penalty when he ruled that Clemens Fritz had fouled Didier Drogba as he challenged for Essien's cross.
Midfielder Michael Ballack, who had earlier been given the penalty taking responsibilities from coach Jose Mourinho, stepped up to show misfiring teammate Frank Lampard how it is done from the spot as he blasted his penalty past Andreas Reinke.
Werder coach Thomas Schaaf believes his side can still qualify for the second round despite a result that leaves them trailing Chelsea and reigning European champions Barcelona.
"We have no right to come to Chelsea and say we should win because not many teams do that and it is no surprise that Barcelona won at home," the 45 year old said.
"After one game it is too early to say how well we will do but there is no reason why we cannot qualify.
"It is like saying the Bundesliga is over after three matches just because one team has more points than the rest."
In Group B, German Champions Bayern Munich also easily dispatched with their opponents when they cruised to a 4-0 victory over Spartak Moscow in Munich.
After the first half had ended goalless the home side found their scoring touch as South Americans Claudio Pizarro and Roque Santa Cruz both scored within four minutes.
German international Bastian Schweinsteiger and substitute Hasan Salihamidzic completed the rout as Spartak fell apart.
"There was nothing special about my half-time team-talk.
Spartak ran their socks off in the first half and we knew they could not do that for 90 minutes," explained Bayern coach Felix Magath.
"As soon as we scored early in the second half the tension was lifted and we scored a few more. Overall I think we deserved to win 4-0."
Portugal’s Sporting Lisbon joined Bayern at the top of Group B when they defeated Italian side Inter Milan 1-0 after a screamer from defender Marco Caneira.
None of the four sides in Group C managed to find the back of the net as the matches between PSV Eindhoven and Liverpool and Galatasaray and Bordeaux both ended goalless.
In Group D action both Valencia and Roma scored four goals in their respective victories over Olympiakos and Shaktar Donetsk.
Former Spanish striker Fernado Morientes scored a hat-trick for new club Valencia as he helped his side to three points after initially trailing to a goal from Michalis Konstantinou.
The goals were also flowing in Rome as the home side made the Ukrainians pay for their earlier profligacy with four goals in the final 23 minutes to wrap up the match in commanding fashion.