Instructional leadership can be explained as an educational leadership approach whereby the school principal engages in a wide range of activities aiming to improve teaching and learning for all students. A recent meta-analysis found that female principals engaged in more active instructional leadership than male counterparts. The current qualitative study sought to understand this gender gap. Data were collected through 59 semi-structured interviews with 36 female principals and 23 male principals from Israel. Data analysis was a four-stage process -- condensing, coding, categorizing, and theorizing. Findings showed that female participants, more frequently than their male counterparts, reported possessing two capabilities that are necessary for instructional leadership: (1) instructional expertise; (2) attention to relationships. Gender theories are employed to explain these findings. Practical implications and further research are discussed.