This final paper analyzes the trend of pertussis (whooping cough) in the City of Zagreb over the period from 2014 to 2023. Through an analysis of epidemiological data, patterns in the number of cases, the impact of demographic factors such as age and gender, and the seasonal distribution of the disease were examined. Special attention was given to the impact of the COVID-19 pandemic on the reduction of reported pertussis cases between 2019 and 2022, as well as the sudden increase in cases in 2023 following the lifting of preventive measures. The pandemic and related measures, such as social distancing and wearing masks, led to reduced transmission of respiratory diseases, including pertussis. However, 2023 saw a dramatic increase in the number of cases, likely due to the removal of preventive measures, decreased population immunity, and the natural cycle of epidemic occurrence. An analysis of the data by age and gender showed that children and young people, particularly those in the 10 to 14-year-old age group, were the most affected by pertussis. Women generally had a higher incidence rate than men, although certain age groups recorded higher numbers of male cases. Seasonal analysis reveals that, with the exception of the extreme year 2023, the highest number of reported cases was recorded during the summer months, while the number of reports was significantly lower in the winter period. The results of this research emphasize the need to improve public health measures, especially vaccination, to ensure the protection of the most vulnerable groups, including children and young people, and to prevent future pertussis outbreaks. Education and public awareness about the importance of vaccination and recognition of pertussis symptoms are also one of the key measures for the prevention of future epidemics.