This study explores the learners’ strategies for heuristic ability in mathematics at the secondary level. The study is qualitative, and the method adopted for obtaining information about the learner’s strategies is a case study. The site selected is Govt. Girls Higher Secondary School Rustam, Mardan, Khyber Pakhtunkhwa, Pakistan. Participants of the study were six in number, selected from science group students of the 9th class based on their interests. A test of non-routine problems was used for the collection of data. Six non-routine problems were given to the students to check their heuristic ability. Non-routine problems were analysed through cognitive strategies. No scoring of students was considered in this study. The researchers categorized the learner’s responses so that students who solved questions by applying complete strategy were marked with the word excellent, the half strategy was marked very good, and unsatisfactory solutions were marked satisfactory. The study investigated learners’ strategies such as making tables, using formulas, guessing, making diagrams, doing trial and error, logical reasoning, non-logical reasoning and looking for patterns. Results show that students who are interested, motivated and have a positive attitude toward learning practice various methods for solving non-routine problems.