Professional development is a critical aspect of education for teachers in the Philippines, who encounter various challenges in addressing the evolving needs of their students and the education system. Using the descriptive cross-sectional technique, the study aimed to identify the practices, challenges, and perceived impact of professional development activities among senior high school teachers. While there are similar studies on the subject, there are few to none which present the specific situation of senior high school teachers in the Philippines. The results showed that the respondents utilized professional development practices in terms of graduate/post-graduate studies to a great extent; FGDs, LACs, and other trainings to a very great extent; research and publication to a very great extent; education innovations to a very great extent; membership in professional organizations to a very great extent; and community service involvement to a very great extent. Of these practices, those in terms of community service involvement were utilized the most while those in terms of graduate/post-graduate studies were utilized the least. In addition, the respondents experienced professional development challenges in terms of teacher-related factors to a great extent; professional development availability, cost, and design to a great extent; and instructional supervision and assistance to a moderate extent. Of these challenges, those in terms of professional development availability, cost, and design were experienced the most while those in terms of instructional supervision and assistance were experienced the least. Furthermore, the respondents perceived the impact of professional development activities to a very great extent. The results also imply the need to underscore involvement in graduate/post-graduate studies in the proposed action plan and to improve the job satisfaction of teachers after engaging in professional development activities. Future researchers may conduct a similar study with the inclusion of the views and experiences of administrators and students as a means of validating the supposed impact of professional development activities as perceived by senior high school teachers.