The aim of this was to find out the reason for low performance in West African Examinations Council final examination in Core Mathematics. The exploratory research design was used for the study. A population of two hundred (200) students; 100 females and males in a breakdown of 50 males and 50 females from SHS and 50 males and 50 females from JHS was used. Richard Quinn's Mathematics Anxiety Rating Scale with a reliability coefficient of 0.90 (p = ?0.001) and validity found to be r = 0.92 (p = ?0.001) was used for data collection. The statistical tool used was the independent T-test comparisons. Results revealed that, mathematics anxiety exists among students in a frequency of 95 in the severe anxiety range of 75%-95%. Out of 200 populations, 47.5% have severe anxiety for mathematics. It was also found that, significant difference exists between SHS female and SHS male. All other comparisons produce no significance. A study of the mean values showed that at the JHS level, the males have higher mathematics anxiety level than the females. At the SHS level, the males have higher mathematics anxiety levels than the females. Further, at the JHS level the males' mathematics anxiety is a little higher than the SHS males. Mathematics anxiety level increases from the JHS to the SHS level. The males have higher mathematics anxiety levels than the females. It is recommended that, Clinical Psychologists, School Counsellors, Guidance and Counselling personnel should urgently take students through systematic desensitization using anxiety hierarchy technique and behaviour therapy using anxiety-relief response to help students eliminate or reduce mathematics anxiety.