Abstarct This paper investigated Perception of Causes of Mass Failure in Mathematics in Senior Secondary School Examination in Olorunda Local Government of Osun State, in Nigeria. The study was descriptive survey research design; the population of the study were all the secondary school students in the Local Government. The sample of the study were 100 teachers selected from 10 secondary schools. The secondary schools were selected using simple random technique, while the students were selected using systematic random method. Structured questionnaire was used to collect data from the respondents the results show that there is significant influence between the perception of male and female teachers, rural and urban teachers, private and public school teachers and trained and untrained teachers of the causes of Mass failure in Mathematics in Olorunda Local Government.