Asthma and COPD are inflammatory diseases of respiratory system. Chronic obstructive pulmonary disease is one of the most prevalent diseases and the leading cause of disability and death worldwide. Improper asthma management leads to increased morbidity as well as economic burden to individuals and societies. Better asthma and KOPB management and care is essential for effective patient care reducing the morbidity and mortality of the disease overall in the country. Inhalers are the common and widely used treatment modality in the asthma and KOPB management. Pharmacological groups which are prescribed are:beta-2-receptor agonists, muscarinic receptor antagonists and corticosteroids. There are numerous inhaler devices available for the drug delivery in patients with asthma and chronic obstructive pulmonary disease: dry-powder inhalers (DPIs), pressurized metered-dose inhalers, soft mist inhalers and nebulizers. Each inhaler has advantages and disadvantages that may influence a patient’s use, satisfaction and compliance with therapy, and ultimately affect clinical outcomes. Desired effects can only be achieved by proper usage with correct technique. In this paper, the emphasis is on the errors that occur while patients use different commercially available inhaler in Croatia. Detected errors while using MDI include: not shaking inhaler before use, not removing the recover peace, incomplete gasp before inhalation, breading too fast, insufficient retention of breath, pressure pump more times, insufficiently covered the mouthpiece and hold the device upside down. The frequency and importance of each error is listed in the paper. Typical mistakes that we associate with DPI are: shaking DPI, incomplete gasp before inhaling, exhaling into the device, slow inhalation, wrong preparation of the inhaler device, the wrong dose adjustment or inability of deep breaths. The most common error and common to all types of inhaler is incomplete gasp before inhalation. All pharmacists encounter patients with respiratory diseases often during their professional career. Competent and knowledgeable pharmacists can raise the standards of patient care and satisfaction within the community and may play an important role to overall disease burden in the society.