This study aimed to find out the practice of continuous assessment in teaching and learning mathematics.The study involved 5second cycle primary schools which were purposely selected from 25 general primary schools. 217 students, 17 mathematics teachers, 5 directors, 3 cluster supervisors and 3 woreda education office experts were involved in the study. The study used both qualitative and quantitative (mixed)approach to conduct the research. Data were collected through questionnaire, interview, observation and document review. Percentage, one sample T-test, and independent sample T-test were statistical methods used to analyze and present the data by using SPSS version 26 software. Findings showed that most teachers use CA during teaching learning mathematics. But there are variations between teachers. Accordingly, it is hardly possible to say CA is implemented effectively in teaching and learning mathematics in the study area. The study concludes that the implementation of continuous assessment is not implemented effectively, teachers and students have positive attitude toward CA. More over; large number of students in class, teachers’ additional workload, large instructional content, lack of clear guide lines, and lack of access forinfrastructures, teacher miss class, and student’s absenteeism, teachers’ lack of training, teachers’ lack of skills and teachers commitment are factors that hinder the implementation of CA. As a result the researcher recommendedthat,to overcome these challengesit is better to employ additional teachers to reduce workload, fulfilling teaching and learning materials, providing students’ CA reports to parents in monthly basis and evaluatingtogether, training teachers and raising their awareness, improving teachers managing ofstudents, mobilizing students and making conducive classrooms.