“Mathematics should be taught on a compulsory basis to all pupils as a part of general education during first ten years of Schooling” - Indian education commission (1964-66) The present study intended to find the effect of multimedia in teaching mathematics at secondary in Dindigul District. The study was conducted on a sample of 60 ninth standard students at secondary level. Tools used were multimedia package and mathematics achievement test. The sample divided in to two groups, experimental group and control group. Both groups equated at their previous examination scores or final examination scores of eighth standard in mathematics subject. The students of experimental group exposed to teaching through multimedia package, whereas the students of control groups taught through conventional method of teaching. Pre-test and post-test equivalent groups design was followed for this study. The result show that the multimedia package prepared by the researcher is more effective and joy full learning for the mathematics achievement test of ninth standard students. It was also found that multimedia proved its effectiveness in teaching mathematics at secondary level over the conventional method.