ObjectivesHealthcare workers (HCWs) are at the frontline of efforts to treat those affected by COVID-19 and prevent its continued spread. This study seeks to assess knowledge, attitude and practice (KAP) as well as training needs and preferences related to COVID-19 among frontline HCWs in Nigeria.SettingA cross-sectional survey was carried out among 1852 HCWs in primary, secondary and tertiary care settings across Nigeria using a 33-item questionnaire.ParticipantsRespondents included doctors, nurses, pharmacy and clinical laboratory professionals who have direct clinical contact with patients at the various healthcare settings.AnalysisExploratory factor analysis (EFA) was used to establish independent factors related to COVID-19 KAP. Analysis of variance was used to identify any differences in the factors among different categories of HCWs.ResultsEFA identified four factors: safety and prevention (factor 1), practice and knowledge (factor 2), control and mitigation (factor 3) and national perceptions (factor 4). Significant group differences were found on three factors: Factor 1 (F(1,1655)=5.79, p=0.0006), factor 3 (F(1,1633)=12.9, p<0.0.0001) and factor 4 (F(1,1655)=7.31, p<0.0001) with doctors scoring higher on these three factors when compared with nurses, pharmaceutical workers and medical laboratory scientist. The most endorsed training need was how to reorganise the workplace to prevent spread of COVID-19. This was chosen by 61.8% of medical laboratory professionals, 55.6% of doctors, 51.7% of nurses and 51.6% of pharmaceutical health workers. The most preferred modes of training were webinars and conferences.ConclusionThere were substantial differences in KAP regarding the COVID-19 pandemic among various categories of frontline HCWs surveyed. There were also group differences on COVID-19 training needs and preferences. Tailored health education and training aimed at enhancing and updating COVID-19 KAP are needed, particularly among non-physician HCWs.