Introduction: A continuous supply of O2 essential for all the cells of body. A deficiency of O2 leads to lowered O2 tension of blood plasma and oxy hemoglobin in the red blood cells.

Objectives: To assess the pre-test level knowledge regarding care of child receiving O2 therapy among interns as measured by student knowledge questionnaire. To evaluate the effectiveness of planned teaching programme regarding care of child receiving O2 therapy among interns in gain of mean post test knowledge score.

Methodology: A random sampling technique was used to select the samples. The sample for the present study consisted of 30 interns studying in a selected School of Nursing at Mangalore. In this study the structured knowledge questionnaire was used for assessing the knowledge regarding care of child receiving O2 therapy among interns.

Result: The results of the study showed that mean post test knowledge score (30.30) was higher than the mean pre test knowledge score (9.53) paired ‘t’ test was used to find out the difference between the mean pre test and post test knowledge score. The calculated t value (7.93) was found to be significant.