The present study aimed at identifying perceptions of the English language-related needs and problems of science and science-education students at Sultan Qaboos University (SQU). More specifically, it addressed three major issues which can be stated as follows: 1. The English language-related needs and problems of science and science-education students in the College of Science at SQU. Three types of needs were investigated. These were the linguistic needs, the communicative needs and the learning needs. 2. The English language proficiency level of science and science education students in the four English language skills (i.e. reading, writing, listening and speaking). 3. The importance level of the four English language skills in students' studies at the university. The sample consisted of 164 science and science-education students and 54 faculty members from the College of Science. The student sample was selected from two instructional levels: third year (semester 5) and fourth year (semester 7). Different types of instruments were used in two different stages of the research. Observation and interviews were used in the preliminary investigation while questionnaires were used in the main investigation. The data were submitted to appropriate statistical techniques consisting mainly of t-test and ANOVA. The reliability coefficient of the questionnaire was found to range between 92 for faculty members' version and .94 for that of students. The main findings of the study can be summarized as follows: While science students perceived learning needs as most problematic, followed by the communicative needs and lastly by the linguistic needs, faculty members, on the other hand, indicated that the communicative needs were most problematic, followed by the linguistic needs and lastly by the learning needs. Whereas science students viewed themselves as best in reading, then writing, followed by listening and lastly speaking, science faculty members, on the other hand, viewed their students' ability as best in listening, followed by reading, then speaking and lastly writing. With regard to students' and faculty members' perceptions of the importance of each skill, students gave more prominence to the speaking skill, followed by writing, then reading and lastly listening. Faculty members, on the other hand, considered writing to be the most important, followed by reading, then listening and lastly speaking. Among the research implications suggested by the results of this study are the following: (1) the need to evaluate the present ESP program at SQU to see the extent to which it meets students' needs and solves their problems, and (2) the need for more qualitative information about students' needs and problems through extensive observation of students in their functioning inside and outside the classroom. With regard to the educational implications, it was recommended that particular attention should be given to those areas in which students experienced most difficulty such as speaking skill and reading habits.