This study aimed of providing baseline information on in-service trainings, teacher factors, and student performance ; and to develop a professional development model for teachers. A total of 53 Fourth Year High School teachers and 2,084 students were randomly taken as participants across Division of Puerto Princesa City, Palawan. The Research and Development (R & D) method, which has two modes of research and design, was utilized in this study. For the research mode. three sets of achievement tests were administered to the students while a survey and a focus group interview were employed to gather data from the teachers.. As regards results of the English, Mathematics, and Science achievement tests, students had low performance in three subject areas in which Science was the lowest. Nevertheless, teachers had high perception and satisfaction regarding the in-service training programs. They also had high levels of teaching efficacy, average level of job satisfaction, and positive attitude towards the teaching profession. Furthermore, results of the Stepwise Multiple Linear Regression showed that teachers' level of satisfaction with the in-service training programs was a significant predictor of their teaching efficacy. It was also found that teaching efficacy, job satisfaction, and attitude were not significant predictors of student performance. All the results found in the research mode were taken as bases for the design and development of the professional development model for teachers. This model aimed at empowering teachers particularly in English, Mathematics and Science by giving them an opportunity to choose their own activities from an array of professional development activities through a contract or a written agreement with their school heads. Likewise, all instruments underwent content and face validity while the analysis of data using descriptive statistics and Multiple Linear Regression were processed through the Statistical Package for the Social Sciences (SPSS) software 17.