Background: the risk of cataract was increased in patients using steroid therapy for long periods in a dose dependent manner. Objectives: assessing the knowledge of Saudi population toward chronic use of steroid therapy impact on cataract. Subjects and Methods: this is a cross sectional study conducted from February 2017 to June 2017 among 918 adult subjects randomly chosen from 15 primary health care centers in KSA. All subjects were asked to fill up a questionnaire that included their demographics and questions about using steroid therapy and it effects. Results: the mean age of included subjects was 58.7 years old, 52% of were males and 48% were females. More than half of included subjects had college degree (51.2%) and 66.8% were working. Only 7.8% of subjects had cataract and 20% of subjects received steroid therapy for more than 4 months per year. The knowledge score was good in 23.3% of subjects and poor in 76.7% of subjects. There was no association between age, gender, and working status but the higher education was significantly associated with good knowledge. Conclusion: there was inadequate knowledge about cataract induced by using steroid therapy among adult Saudi population and no significant impact of age, gender and working status has been evidenced. But the higher education was associated with higher levels of good knowledge.