The study examined gender disparity, implications in students' academic performance in biology, chemistry, physics and mathematics in secondary schools in Buea Sub Division, Cameroon. The Sustainable Development Goal 4 which focused "Ensure inclusive and equitable quality education and promote lifelong learning for all on adopted in September 2015 by the United Nations marked a paradigm shift in education goal which previously focussed on ensuring access to education to equitable quality education. The research objective was to investigate students related causes of gender disparity in students' academic performance in biology, chemistry, physics and mathematics. The survey design was used and data were collected from participants in nine secondary schools and the Regional Delegation of Secondary Education with a sample size of 251 participants. Instruments used for data collection were questionnaire, interview guide, observation check list and focus group discussion. Data were analysed using thematic analysis, descriptive and inferential statistics. Findings revealed that student related factors like negative attitudes towards science subjects which resulted from low self esteem, negative stereotype and lack of parental support caused gender disparity in performance. This study informs current discourse on the 21st century science classroom challenges and provides a baseline data for science education reforms. Mary-Ann Awasiri Takwe "Gender Disparity, Implications to Students' Academic Performance in Science Subjects in Secondary Schools in Buea Sub-Division, Cameroon" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26763.pdf