Purpose: The study determined the level of health literacy in terms of knowledge of drug abuse as well as its application in making healthy decisions among secondary school students in Ogbia Local Government Area of Bayelsa State, Nigeria. Method: Three research questions and one hypothesis guided the study. Survey-design was utilised and 260 senior secondary three (SS3) students were selected through simple random sampling technique. The instrument for data collection was a questionnaire consisting of two parts: part one was on knowledge test items on drug abuse, while part two was application of knowledge of drug abuse in decision making. The instrument had a reliability coefficient of r = 0.81 using split half reliability method. The statistics used in data analyses were mean, standard deviation and Pearson Product Moment Correlation. Results: The result shows that the mean score of the knowledge of drug abuse was 59.28, indicating that participants had fair knowledge of drug abuse but the hypothesis tested, revealed no relationship between knowledge and application. Conclusion: The application of the knowledge learnt about drug abuse should be put into practice. Promoting health at this stage of life (adolescence) represents a potentially cost-effective approach to enhancing healthy child development, promoting long-term health and addressing health early in life. Recommendation: It was therefore recommended that more emphasis should be place on the teaching of the knowledge of drug as well its application to everyday living.