Background: Capnography is the gold standard for confirming endotracheal tube placement, help guide ventilation in conjunction with blood gases, as it provides an excellent picture of the respiratory process. Aim: Evaluate the effect of self-learning package on nurses' knowledge, interpretation and practice regard measuring End-Carbon dioxide by capnography. Design: A quasi-experimental (Pretest-Posttest design) was used. Setting: The study was carried in medicine intensive care units at Ain Shams University hospital. Subjects: All available nurses (45) in the previous mentioned setting. Tools: Structured nurses' assessment tool; included: part (I): Nurses' characteristics, part (II): Nurses' knowledge assessment questionnaire, part (III): Nurses' capnography waveforms diagram interpretation and Part (IV): Nurses' practice observational checklist. Results:  showed that there was an obvious improvement in the studied nurses' total satisfactory level of knowledge, interpretation and practice post implementation of the self-learning package with a positive correlation between the independent variables of the study (knowledge, interpretation & practice) r = 0.71 at P< 0.001, r = 0.07 at P< 0.04 & r=0.52 at P< 0.05 respectively.   Conclusion: This study concluded that self-learning package implementation had a positive effect in improving nurses' knowledge, interpretation and practice regard measuring end-carbon dioxide by capnography. Recommendation: Provide periodic in-service training based on best practice guidelines for nurses who work in intensive care units and emergency units regarding measuring End-Carbon dioxide by capnography.