The aim of the study to assess the knowledge regarding care of newborns undergoing phototherapy among staff nurses by using a non experimental descriptive survey design with the help of a self structured questionnaire which contains 30 items of questions. Non Probability purposive sampling technique was used in this study. The results showed that, out of 30 samples, 70% have moderate knowledge, 30% have inadequate level of knowledge and unfortunately, no one has adequate knowledge regarding phototherapy and there is no significant association with level of knowledge and selected demographic variables like age, educational qualification, professional experience and so on (p>0.05). In conclusion, Nurses has to acquire more knowledge on care of newborns undergoing phototherapy in order to prevent the ill effects from faulty practices of delivering phototherapy.