Science teachers' perceptions and understanding of Nature of Science (NOS) is central to scientific literacy worldwide. This qualitative case study aimed to explore the perceptions of nine secondary school science teachers about NOS from six private schools of Gilgit. The three important tenets of NOS relevant to school science were, science being tentative in nature, empirical nature of science and scientific laws and theories. The schools and participants; three teachers from each discipline; chemistry, biology and physics were chosen through purposive sampling. Data was collected via two tools which were written in English and Urdu. The research tool, Views of Nature of Science (VoNOS) had six open-ended questions to be answered in written, while Nature of Science Research Protocol (NOSRP) was a semi-structured interview tool with four critical incidents to elicit verbal responses which were audio-taped with their consent. The data was thematically analyzed after transcription, verbatim, translation from Urdu to English and coding.Their responses were categorized into the three predominant themes as informed, adequate and inadequate by using a rubric adapted from Khan (2014). The results were noteworthy; it was revealed that despite not having read explicitly about NOS participants' held informed perceptions about science being tentative and empirical NOS. They believe that science is not fixed rather it is an on-going process, based on observation, experimentation and inferences. However, majority had adequate perceptions about laws and theories. They believed that that theories and laws are different but sometimes theories can convert into laws when proven right. Hence, this study recommends that the stake holders need to revisit the content of textbooks for updated knowledge about laws and theories and add many examples regarding it. The findings of this study can help science teachers, educators and researchers to understand the three aspects of NOS and become aware of the misconceptions about them.