The purpose of this study was to examine the factors contributing to poor performance of mathematics in Igunga District Community Secondary Schools. The objectives of the study were: to find out the trend in performance of Mathematics in community secondary schools, to find out the school-based factors that influence student performance in Mathematics in community secondary schools, and to find out the strategies to put in place to improve the poor performance in Mathematics in community secondary schools. The study adopted a descriptive survey design. Data was collected using Questionnaires, Classroom observation, and Documentary review. The instruments validity and the reliability were improved by a pilot study; the reliability coefficient of 0.75 was obtained. The Head of community Secondary Schools, mathematics teachers and students were drawn in as population for the study. These were administered on a sample of 5 Head of schools, 10 mathematics teachers, and 175 students respectively selected from five community secondary schools in Igunga District. Quantitative data collected were coded and analyzed using the Statistical Package for Social Science (SPSS) version 20.0. Secondly, the qualitative data obtained were analyzed by considering major themes to extract relevant information. Ethical considerations were observed during all stages of the study. Findings indicated that the major problems associated with students’ poor performance in mathematics in community secondary schools included; lack of qualified mathematics teachers, large class sizes, teaching methods which are not student-centered, and shortage of teaching and learning resources. All the sampled schools had mathematics teachers not more than 50% of the school requirement. Large class size was reported by 80% of the respondents. With regard to teaching methods, lecture method was superior to participatory methods by 80%. Above 75% of the respondents reported that there was acute shortage of teaching and learning materials in community secondary schools. Making improvement on these factors and sensitization of the local community to remove practices which disallow student’s effective involvement in learning mathematics could improve performance in the subject. The findings of the study may assist educational administrators, planners and policy makers in making appropriate strategies to solve the problem. This study also may help in the formulation of policies for the improvement of mathematics performance in the country. The report also will remain as a reference for future reforms, which will be helpful to local government administrators especially those working in the education sector, Non-governmental organizations and the society as a whole in improving students’ performance in mathematics particularly those of Igunga District community. Teachers may directly benefit from the findings by improving their management and teaching techniques. On the other hand, through this study, it is expected that students will acquire knowledge about various factors influencing poor performance in mathematics which lead to personal improvement hence better math performance in their examinations. Researchers may use the study as a reference. It was recommended that the government, District council, Head of schools, mathematics teachers and students should play their role to improve the performance in mathematics.