To understand the process by which Spiritual Intelligence (SI) is developed a group of 21 Tabrizi high school students, along with their teachers and people who interacted with them, were interviewed in a semi-structured way, to the point of data saturation. The collected data were content analyzed and their validity was increased through triangulation and participants’ feedback. Results show that the process of developing SI is rather complex as it is affected by both internal and external factors and consequently can only be described as a set of intertwined stages that their exact order is not fixed, yet with inferences made from the participants’ life experiences and their interpretation of findings, it can be said that the process starts with the realization of the SI’s importance and goes through stages of model selection and gaining of spiritual experiences that lead to consequences among which internal peace and quiet which is conceptualized as the central phenomenon in this research.