Performance in physics subject in secondary schools, particularly in secondary schools for the Hearing Impaired (HI) has been a matter of great concern in Kenya. Attempts including in- service programmes for science teachers such as Strengthening Mathematics and Science in Secondary Education (SMASSE) have been made to improve the situation but not much tangible fruits have been realized. Surveys have always shown low performance in the subject in most secondary schools for the HI in most parts of the country. Some secondary schools for the HI have even stopped offering the subject at forms three and four while some do not offer the subject at all levels. The purpose of this study was to examine the aspects of physics curriculum that influence performance of students with HI in secondary schools in Western Kenya. Objectives were to establish the influence of time on task on performance of student s with HI in physics, determine the influence of mathematical content on performance of students with HI in physics, examine the influence of teaching methods used by teachers on performance of students with HI in physics, and to find out the influence of curriculum support for teachers on performance of students with HI in physics. The study adopted concurrent triangulation design of mixed methods approach. The study used the constructivist theory of learning. The study population consisted of 4 principals, 59 teachers, 816 students and 4 curriculum support officers (CSO). Schools, teachers and students were selected purposively while saturated sampling technique was used to select the principals and CSOs. The study sample composed of 4 principals, 7 teachers of physics, 147 students and 4 CSOs. Questionnaires, in-depth interviews, observation schedules and document analysis guide were used for data collection. Reliability was addressed by use of Cronbach’s Alpha Internal Consistency while validity was addressed through expert judgment by supervisors and lecturers from the School of Education. Quantitative data was analyzed using descriptive statistics through the use of charts, frequency tables and percentages. Qualitative data was organized and analyzed using thematic analysis. The research findings revealed that time on task influences performance of learners with HI in physics. Mathematical calculations in physics influences performance of learners with HI in the subject (r = .930; k = .898). This denotes that mathematical content in physics has a high positive correlation with performance of HI students in the subject. Methods used for teaching learners with HI influences their performance in physics. The main methods found out were ICT integration, discussions and practical work. Finally, curriculum support for teachers also influences performance of learners with HI in physics. The study concluded that time on task, mathematical content; teaching methods and curriculum support for teachers are critical aspects influencing the performance of students with HI in physics. It was recommended among others that physics syllabus be adapted to suit the unique needs of learners with HI. Teachers teaching learners with HI were encouraged to embrace remedial teaching to help the learners catch up with their hearing peers, and use more of visual learning and learner centered methods of teaching where learners are actively involved in the learning process rather than being passive recipients of knowledge. Increase in in-service programs for special education teachers was also recommended facilitated by specialists to help address teacher difficulties as well as learner challenges when teaching learners with HI. Based on the findings, a study on monitoring and evaluation and its impact on curriculum implementation in special schools would expound the current study.