BACKGROUND: The consequences of the war and siege in Tigray on pertussis cases have not been previously assessed. METHOD: All children diagnosed with pertussis in Ayder Hospital two years before and during the war and siege of Tigray. Data were collected using ODK software and analysed with SPSS version 22. Descriptive statistics, chi-square tests, and the Mann-Whitney U test were used to assess the impact of the war and siege. A p-value of less than 0.05 was considered statistically significant. RESULTS: Data from a total of 144 children were analysed, most of whom (78.5%, 113/144) had been admitted during the war and siege period. Males accounted for 53.5% of the cases. Statistically significant differences were observed during the war and siege compared to pre-war time with age ( CONCLUSION: Pertussis outbreaks during the war and siege in Tigray were associated with poorer outcomes across all age groups.