Background: Following the example of other countries, it is very important to educate patients on the correct use of inhalers by properly trained healthcare professionals, including pharmacists. Objectives: The aim of the study was to assess the quality and comprehensiveness of professional advice given by pharmacists on the use of inhalers, which was determined by the pharmacists’ level of training. Methods: The study was conducted from June 2019 to March 2020. 150 pharmacists from Poznan and Warsaw (Poland) were involved. Before the study began, the professional education of 240 pharmacists was conducted in Warsaw to implement standard operating procedures. The study used the model of a mystery shopper. Results: The conversation with a trained pharmacist lasted on average 5.5 min, with an untrained one—3.0 min (p < 0.0001). Placebo inhalers were used more often by trained pharmacists during patients’ education (p < 0.0001). Moreover, 10.3% of untrained pharmacists did not provide any education. Additionally, untrained employees’ quality of advice was assessed on an average of 3.5 points, while trained ones—7.6 points (p < 0.0001). Conclusions: This study has shown that there is a need for professional training among pharmacists in Poland, which translates into better patient education in the field of inhalation techniques.