The study was designed to investigate how Continuous Assessment (henceforth, CA) marks in Educational Administration and Planning course for undergraduate students will significantly predict their final examination marks. The study adopted ex post facto research design with a total of 221 undergraduates, who registered for a course in the second semester, at the Faculty of Education, Osun State University, Nigeria. The undergraduates' scores in continuous assessment and examination scores at the end of the semester formed the data for the study. The data collected were analysed using descriptive and inferential statistics. The results revealed that Biology students had the highest mean value when compared with the mean of undergraduates from other specialised areas. The regression analysis result (F1, 219=40.414, p<0.05) reveals that the CA significantly predicts undergraduate students' performance in semester examination and made the best contribution to students' performance in Educational Administration and Planning. From the findings, it was concluded that continuous assessment scores are a good predictor of undergraduate students' performance in semester examination. It was recommended that there should be thorough supervision of the CA, all process must be monitored in Nigerian Universities for quality assurance.