Purpose: The purpose of this study is to find out how much influence nursing students’ environmental consciousness and knowledge of medical waste have on their attitudes toward medical waste. Methods: The subjects were 211 nursing students recruited from 2 universities. Data were collected with a structured self-report questionnaire comprising measures of environmental consciousness, and knowledge of and attitude toward medical waste. Data analysis was conducted with the SPSS/WIN 25.0 program. Results: A total of 211 copies of the questionnaire were used for the final analysis, except for 9 untrusted responses out of 220 that included missing values. Those subjects’ environmental consciousness who received environmental education in middle and high schools was higher (t=3.15, p=.002). The higher their grades, the better their knowledge of medical waste (F=3.40, p=.035). Those subjects’ knowledge of medical waste who received medical waste education was relatively high (t=3.14, p=.002). Those subjects with clinical practice experience had more sensitive attitudes toward medical waste (t=2.06, p=.041). Those subjects’ attitudes toward Medical waste who received medical waste education at the universities were relatively high (t=2.04, p=.043). The subjects’ environmental consciousness was positively correlated with their attitudes toward medical waste (r=.44, p<.001). The most influential factor in their attitudes toward medical waste is their environmental attitudes and medical waste education. Conclusion: The higher the nursing students’ environmental consciousness, the higher their attitudes toward medical waste. It is necessary to provide environment and medical waste education for nursing students in order to strengthen their environmental consciousness and attitude toward medical waste.