Objectives: Verify the effectiveness of autoclaves using chemical indicators in the pre-professional clinics of a higher institution. Materials and methods: An observational study was carried out in pre-professional clinics of a higher training institution for dentists in the city of Cuenca, Ecuador. Ninety-four readings with chemical indicators were used in two functional autoclaves distributed among three clinics. The evaluation was based on the 3M® control and chemical integrator 3M® Attest® 1243B, with results classified as “Accepted” or “Rejected.” The indicators were placed in various locations within the autoclaves and monitored for four weeks, at two specific times of the day. Results: Of the 94 chemical indicators used, 63.8% resulted in “Accepted,” evidencing the effectiveness of the sterilization, while 36.2% were classified as “Rejected,” indicating unsatis...