Objectives: Air pollution has become a critical environmental issue, which severely threatens the well-being of asthma patients. The quality of life of these patients, when exposed to air pollutants such as particulate matter 10 (PM₁₀), has been poorly studied. The current research examined the association between the concentration of PM₁₀ in the air and the quality of life of patients with asthma. Material and Methods: The study group consisted of 300 adult asthma patients treated in 2 allergy outpatient clinics in Kraków, who declared they would not leave the city in the 14-day study period. Daily concentrations of PM₁₀ from air monitoring stations were recorded over a period of 2 weeks, following which the patients filled out the standardized Asthma Quality of Life Questionnaire (AQLQ) regarding the monitored period to assess the total quality of life and its 4 domains (symptoms, limitation of activity, emotional functioning and environmental stimuli). Results: The average PM₁₀ exposure was 65.2 μg/m³ and only 30% of the patients were exposed to values of ≤50 μg/m³, i.e., the highest 24-h threshold value considered acceptable by the World Health Organization. The observed effect of an increased level of exposure to airborne PM₁₀ was associated with reduced scores in AQLQ from 0.40 at the medium level to 0.46 at the high level, in comparison to the low level. The total score of the asthma-related quality of life and its domains showed poorer outcomes as the concentration of PM₁₀ was increasing (every 0.08 pt per a 10 μg/m³ increase). Conclusions: The increase in the concentration of PM₁₀ in the air impacts on the overall quality of life and its particular domains in people with exceptional predispositions, such as patients with bronchial asthma. Physicians taking care of asthma patients should pay special attention to the quality of patient’s life in response to the course and control of that illness, in relation to air pollution. Int J Occup Med Environ Health. 2020;33(3):311–24