Countries like Ethiopia have had to make difficult decisions to balance between the demands of the COVID-19 pandemic and maintaining the essential health service delivery. We assessed the effect of preventive COVID-19 measures on essential healthcare services in selected health facilities of Ethiopia. In a comparative cross-sectional study, we analyzed and compared data from seven health facilities over two periods: the pre-COVID-19 period before the first reported COVID-19 case in the country and during the COVID-19 period. Data were summarized using descriptive statistics and the independent t test. During the COVID-19 period the average number of monthly patient visits in the emergency department, pediatrics outpatient, and adult outpatient dropped by 27%, 30%, and 27%, respectively compared with the pre-COVID-19 period. Family planning; institutional delivery; childhood immunization; antenatal care-, hypertension- and diabetic patient follow-up, did not vary significantly between pre-COVID-19 and during COVID-19. Moreover, the monthly average number of tuberculosis (TB) and HIV patients who visited health facilities for drug refill and clinical evaluation did not vary significantly during the two periods. In conclusion, the study highlights that the effect of public restrictions to mitigate the COVID-19 pandemic on essential care systems should be considered.