The purpose of the study was to investigate Junior High School science teachers' knowledge about contextualised science instruction. The study employed descriptive survey design to collect data. A test, Test of Science Teacher Knowledge of Contextualised Science Instruction was developed and administered to collect data on teachers' knowledge of contextualised science instruction from 204 (180 males and 24 females) Junior High School science teachers. Descriptive and correlational data analyses were performed on the data collected. Some key findings that emerged in the study were: Majority of the teachers' knowledge about contextualised science instruction was weak but correlated positively and significantly with their highest professional qualification. A number of recommendations were made to the Ministry of education and Ghana Education Service: A policy statement should be made in the curriculum to indicate that science teaching should be contextualised. Another policy should be fashioned to compel institutions that train science teachers to include contextualisation of science instruction in their science methodology courses.