The Premier League champions said after the encounter in March that "a number of Chelsea fans were hurt" in incidents outside Camp Nou prior to kick-off.
After conducting an internal investigation, Chelsea released a statement on Friday to confirm a complaint has been filed with European football's governing body.
"Following the match, we issued a plea for information to those fans who may have been involved in these incidents," the Chelsea statement said.
"This resulted in an unprecedented response, with a large number of individuals coming forward to complain in relation to poor organisation, lack of crowd control, brutality on the part of stewards and police and exposure to generally unsafe conditions.
"Chelsea takes the safety of our fans, both at home and away, extremely seriously, and this not what we expect when attending events organised by UEFA or its member clubs.
"We thank those supporters who shared their experiences to help form our report and will now await a response from UEFA."
UEFA confirmed to Omnisport that an investigation into the matter is ongoing, while Barcelona had not responded to a request for comment.
Chelsea were knocked out by Barcelona in the round of 16, losing 4-1 on aggregate to the Catalan giants after a 3-0 second-leg defeat at Camp Nou.