This study on the Physics Instruction and teaching performance in Cagayan State University aimed to know if there is relationship between them. Specifically, this study was proposed to answer how professionally qualified are the Physics teachers with reference to highest educational attainment, years in service, years in teaching Physics, in-service trainings related to Physics, performance rating, how far the learning objectives were emphasized, the extent to which the teaching strategies were used and the consistency of the evaluation with the learning objectives and problems met by the teachers on the nature of students, instructional facilities and administrative support. The study also looked into the problems encountered by the teachers in terms of the nature of students, instructional facilities and supervisory support. Physics teachers in all the campuses served as respondents in the study. Descriptive statistics like frequency counts, percentages, mean and weighted mean were employed to analyze pertinent data regarding the educational qualification of the respondents in relation to teaching experience, in-service trainings, faculty rank and performance rating. Finally, Pearson-R was used to determine the relationship of the Physics instruction and the teachers’ teaching performance. Results of the study revealed that the Physics teachers in the Cagayan State University are qualified to teach Physics courses in the University. Most of them are masters’ degree holders in Physics/Physics Education. Some finished MAT-Physics and MTE-Physics. From the group, three (3) are earning units in the Doctoral program already. The respondents occupy academic ranks that are consistent with the educational qualification they are holding during the conduct of the study. Significant relationship was revealed from the findings on the 1) frequency of use of the teaching strategies, and 2) problems met on the nature of students, instructional facilities and supervisory support. Finally, findings unfold that there exists no significant relationship between Physics instruction and teachers’ teaching performance.