Since the introduction of the concept of “psychological capital” (consisting of four components: self-efficacy, hope, optimism, and resiliency) numerous studies have been conducted in Iran and in the world. Difficulty of reading hundreds of empirical published papers on the aforementioned concept makes it crucial to illustrate a big picture of the research that has been done. This paper, using narrative review method, introduces, categorizes, and evaluates studies that Iranians have conducted on psychological capital. Research has shown that psychological capital is associated with favorite variables in the fields of work (like job satisfaction, organizational citizen behavior, work performance, organizational commitment, and job order), marital (such as marital satisfaction, marital intimacy, and conflict resolution), health (such as decreased depression and anxiety and increased positive psychological functioning such as happiness), education (such as educational achievement, performance, and motive), and religion and spirituality (such as religious coping, spiritual attitude, Islamic life-style, and belief growth). Additionally, two sets of psychological capital-related therapeutic and educational interventions (interventions based on psychological capital to increase performance and various psychological interventions to increase psychological capital) have been proved effective. This paper introduces the concept of psychological capital to the readers and provides a big picture of related empirical studies which shows its desired positive psycho-social outcomes in various domains including work, family, health care, and education.