Background Asthma symptoms can be triggered by a variety of factors commonly referred to as “triggers”. Some of these factors can also induce severe asthma exacerbations. Thus, it can be assumed that actions taken against such triggers may prevent the progression of the disease. However, limited data exist on the clinical importance of these triggers in patients with chronic obstructive pulmonary disease (COPD). Objective To compare the effect of triggers on symptoms and actions taken against certain modifiable triggers in patients with asthma and COPD. Methods The study was conducted in a university hospital between June 2009 and June 2010. Patients with asthma and COPD were asked to complete a questionnaire in which both the factors triggering symptoms and the actions taken against several triggers were assessed. Results Three hundred consecutive adult patients (150 asthma, 150 COPD) were enrolled to the study. The frequency of triggering factors was similar in both groups. Vaccination rates for influenza and pneumococcus were significantly higher in patients with COPD. However, such anti-allergic approaches as the use of strategies to decrease dust exposure, the use of anti-mite bed sheets, and the removal of pets from the home were more commonly employed by asthmatic patients. Conclusion This study revealed that certain triggers affected COPD and asthma patients to the same degree. Therefore, triggers and strategies for controlling modifiable triggers should be more concentrated on during education in both groups. However, the preventive effect of these strategies on disease progression, particularly in patients with COPD, needs clarification.