Girls’ education is one of the most discussed issues in the world. This is because girls’ education is affected by many factors. The purpose of this study was to examine the factors that affect girls’ academic performance in Primary School Leaving Examination in public primary schools in Kishapu District in Shinyanga Region. The objectives of the study were; social-cultural factors that affect girls’ academic performance, school based factors that affect girls’ academic performance and ways forward for the girls’ success in Primary School Leaving Examination. The study adopted a mixed research approach and descriptive survey design. Study sample consisted of 50 respondents that included 20 teachers, 15 students and 15 parents who filled in questionnaires and were chosen using random sampling. The data was collected through questionnaire and interview and then analyzed using Statistical Package of Social Science (SPSS) for quantitative data and descriptive analysis for qualitative data. The findings revealed that early marriage, early pregnancy, absenteeism, love affairs, boy child preference, misconception on girls and peer influence are factors that affect girls’ academic performance in Primary School Leaving Examination. It was recommended that all the problems that affect girls’ academic performance should be solved. There should be strengthening of counseling departments by employing professional counselors. Also building of special rooms for the girls during menstruation period should be put into consideration.