Background. Coughing, being a clinical symptom of numerous diseases is the cause to visit doctors of various specialties, but most often general practitioners. Up to 30% of visits to a general practitioner are somehow related to the development of cough at night. In real clinical practice, serious diagnostic problems arise when examining patients with the so-called subacute cough, one of the causes of which is pertussis. Description of the clinical case. Patient K., 22 years old, visited a pulmonologist 04/17/2019, with complaints of a dry, prolonged paroxysmal cough. On February 22, 2019, she became acutely ill with a subfebrile temperature, a sharp weakness, lightheadedness and cough. The condition was diagnosed as ARVI, acute bronchitis, and bronchial asthma was assumed. She was treated with acetylcysteine, berodual, ambroxol, but without any improvement. Using ELISA, pertussis was detected in the patient. Against the background of the use of a complex preparation containing release-active antibodies, she noted a decrease in the severity and frequency of day and night cough. Daytime cough was completely stopped on the 4th day, and night cough - on the 7th day of treatment. Conclusion. This clinical case shows that in a routine practice, a physician, observing a patient with subacute cough, most often suggests common diagnoses, such as pharyngitis, laryngitis, prolonged course of acute bronchitis or the onset of bronchial asthma. Meanwhile, in the practice of any doctor, there may be cases of pertussis in adults, with a cough as main complaint, which does not fit into the framework of common diseases and does not respond to standard therapy.