Los Rojiblancos failed to find a way through to make it just five points from the last 12 on offer, meaning that Barca are now 12 clear with five games to go.
Betis, who headed into the match on the back of six successive wins, remain fifth in the Spanish top flight and still have an outside chance of making the top four.
Fernando Torres, filling in for the benched Antoine Griezmann, came close to making a breakthrough in the opening quarter of the match when his shot was cleared off the line by Algerian defender Aissa Mandi.
A chance also came and went for Saul Niguez, who struck the crossbar as Atletico - still without back-to-back wins in two months - closed in on a goal.
The 23-year-old attacker also headed just wide in the final 15 minutes, but it was Betis who accrued more shots on target - four to Atleti's two.
In the end, though, neither team could show enough quality in the final third and saw the points shared in the Spanish capital.
ATLETICO MADRID (4-4-2): Oblak; Juanfran (Vrsaljko 65'), Savic, Gimenez, Lucas Hernandez; Vitolo (Koke 63'), Thomas, Gabi, Saul; Correa (Griezmann 63'), Torres
REAL BETIS (5-3-2): Gimenez (Lopez 39'); Barragan, Mandi, Bartra, Amat, Junior; Fabian, Javi Garcia, Tello (Campbell 83'); Boudebouz (Joaquin 65'), Loren