Brake testing of vehicles is one of the most important tests performed in technical–mechanical overhaul workshops (TMOWs). During this test, fine and ultrafine particles are emitted, exposing workers to health risks. A mixed descriptive observational study was conducted in 10 TMOWs in Armenia (Colombia), where particle sampling was performed using the NIOSH 0600 method. One third of the samples were sent for SEM analysis to determine their chemical composition and particle size. The average occupational exposure was 24.31 mg/m3, almost 10 times higher than the threshold limit value for ultrafine particles. The range of particle sizes was from 1.12 to 54.33 µm, with an arithmetic mean of 14.89 µm. The ultrafine size ranged from 198 nm to 798 nm. Traces of components of refractory materials, fiberglass, wollastonite, and thermoplastics, among others, typical of brake pads, were found. This research allows us to confirm the presence of fine and ultrafine particles in TMOW brake tests. Therefore, we recommend improvement actions based on epidemiological surveillance programs of the respiratory health of workers.