Beginning 2003, the Education Ministry of Malaysia implemented a new policy of teaching Mathematics and Science in English. The rationale for teaching Maths. and Science in English is to enhance understanding of these subjects, as well as to enable Malaysians to keep up with the latest developments and compete in these two areas through English. This study examines the language needs of a group of secondary school Science teachers, in particular their perceptions of their English language needs. The perceptions of the Principal of the school and the Head of the Science Dept. about the English language needs of these Science teachers were also examined. Data were obtained through questionnaires, interviews and classroom observation. The findings indicate that the teachers perceived that they needed to improve their speaking skills and grammar. The Principal and the Head of the Science Dept. also perceived the main English language needs of the teachers as being speaking and grammar. The findings derived from this study can be used to design an appropriate English course for the teachers so that they can teach Science in English more confidently and effectively.