According to a United Nations Office on Drugs and Crime (UNODC) Report (2005), some 200 million people, or 5 percent of the world’s population aged 15 - 64 have used drugs at least once in the last 12 months – 15 million more than the previous year’s estimate. It is to this effect that this study seeks to determine the Effect of Drug Abuse on Students’ Academic Achievement (a Case Study of Federal University of Agriculture Makurdi). The study covers the students of Federal University of Agriculture Makurdi. The study was generally based on descriptive survey research design. The population of the study consists of all the 400 level students of the Department of Science Education, a sample of seventy (70) students from Statistics/Computer Science option were selected for this study. Multistage sampling procedure was adopted to select the college and proportionate stratified sampling technique was used to select the department; purposive sampling technique was used to select the course option which makes up the sample size. The data collected was analyzed using simple counts, frequencies, mean and Standard Deviation statistical analysis. From the findings, it has been discovered that drug abuse has a remarkable effect on students’ academic achievement. The use of drug abuse by students of University of Agriculture Makurdi needs to be discouraged. This is because; the continued abuse of drugs among these students can likely have adverse effects on their academic performance.