Pedro Rios opened the scoring for the hosts in the 51st minute but Jorge Molina's leveller midway through the second half ensured the points were shared.
Levante came into the final day of the season in 11th place in La Liga but still in with a shout of reaching Europe next season.
For that to happen, they needed to beat Betis and hope Sevilla lost at home to Champions League-chasing Valencia and Getafe were beaten at lowly Granada.
While Getafe obliged, Sevilla's 4-3 win allied to Levante's stalemate left Juan Ignacio Martinez's men still mired in 11th place, four points shy of ninth place and what could be the final European berth depending on the outcome of appeals lodged by Malaga and Rayo Vallecano against their respective continental bans.
Betis, meanwhile, can reflect on an impressive season that has delivered a seventh-placed finish and the prize of a place in the Europa League qualifiers.
After a low key opening 45 minutes, the game sparked into life six minutes into the second period as Levante took the lead.
Nikos Karabelas had a telling contribution from the left channel, his pinpoint cross evading the Betis backline and falling for Rios, who directed a header low into the left corner.
Ruben Garcia almost doubled the lead minutes later but Casto was the equal of his strike from the edge of the area.
Betis pulled level with a goal of some quality in the 67th minute as Molina picked up the ball in a dangerous position before taking aim from 20 yards with a fierce drive into the top-right corner.
Either side could have gone on and taken the three points had they felt inclined, but with Betis already assured of a place in Europe and Levante no doubt aware of results elsewhere, the game tailed off into a glorified end-of-season kickabout.