Malaria is a public health problem compounded with a widespread emergence of drug-resistant Plasmodium falciparum which necessitated the formulation of a new antimalarial drug policy (AMP). This study was designed to assess adherence to the policy among physicians in health facilities in Delta state, Nigeria. Cross-sectional, analytic study. Data were collected with a semi-structured questionnaire. Two secondary and one tertiary health facilities in Delta State, Nigeria. Physicians selected with a simple random technique from the facilities. Prescribing pattern of antimalarial drugs and adherence to WHO treatment guideline among doctors. Majority (90.8%) of respondents believed the antimalarial policy (AMP) should be strictly adhered to, although three-fifth (61.0%) of them rated its performance as poor. The level of adherence to the national antimalarial drug policy was high (78.5%) as most doctors prescribed Arthemeter-Lumefantrine, AL for uncomplicated malaria however barely two-fifth (35.4%) adhered to prescribing injectable Artesunate for complicated malaria. AL, (71.9%) was the most prescribed antimalarial drug for uncomplicated malaria The most prescribed antimalarial drugs for complicated malaria was artesunate (40.0%) followed by quinine (27.6%) and artemether (26.7%); although, chloroquine was also prescribed. The level of adherence to AMP among doctors was sub-optimal. Continuous education of doctors on the new AMP is needed to achieve malarial control. No funding was received for this study.