This descriptive-correlational study determined the 21st-century digital skills, technology integration in instruction, and challenges encountered in integrating technology. The participants in this study were composed of ninety-five Senior High School teachers in Muntinlupa National High School. The study sought to find a significant association between 21st-century digital skills and level of technology integration in instruction; challenges encountered and the level of technology integration of teachers in instruction. The study revealed that the majority of the respondents were female, aged 40 to 49 years old, acquired MA units, 7 – 12 years of teaching experience, and attended less than 3 related training on technology integration in instructions for the last past 6 months. Findings showed that the level of 21st-century digital skills and level of technology integration in instructions of the SHS teachers was very high. Teachers highly used video conferencing software such as Zoom, Microsoft Teams, GoogleMeet, Cisco, WebEx, and others as the technology they integrate for their instructions. The challenges experienced by teachers in integrating technology in instructions were the following; poor internet connection, students' lack of support system, limited electronic materials and equipment, and lack of technological support from the school experts. Senior high school teachers aged 40 to 49 have higher skills in the information of 21st-century digital skills than teachers aged 50 and above. And, female senior high school teachers have higher skills in communication, collaboration, and problem-solving in 21st-century digital skills than male senior high school teachers. Meanwhile, the teachers’ level of technology integration in instruction and the challenges encountered in integrating technology were the same regardless of teachers’ profiles. The result further revealed that the higher the 21st-century digital skills of the teachers, the higher the teachers’ level of technology integration in instructions. And, the more challenges teachers encountered in integrating technology into instructions, the higher their level of technology integration into instructions.