This study assessed the demographic characteristics of students' performance in Mathematics in senior secondary Certificate Examination in Delta Central Senatorial District of Delta State. The purpose of the study is to assess the relationship between gender, location, socio-economic status and students' performance in Mathematics in Senior Secondary Certificate Examination. The ex-post facto research design was used for the study. The population of the study is 15,170 SS3. A sample of 759 students was randomly selected from the total population using simple random sampling technique of balloting and stratified random sampling technique. Four research questions and four hypotheses were raised to guide the study. The instrument used for the study was a 40-item multiple choice senior secondary Mathematics Achievement test (SSMAT). Multiple regressions were used for the analysis. The study established that gender and socio-economic status contributed to students' performance in Mathematics in senior secondary certificate examination. Recommendation was made based on the findings of the study.