Background: Immunization provides resistance to infectious diseases by administration of vaccine. According to WHO in 2016 the under five child mortality rate was 45 per 1000 live births in India. The child mortality rate in Uttarakhand was 32 per 1000 live births in 2013 as per the survey conducted by the registrar general of India. Objective: To assess knowledge regarding importance of immunization among parents of under five children. Methodology: A quantitative Research Approach was used with non experimental descriptive research design. Research was conducted among 100 parents of under five children in Dehradun, selected using convenient sampling technique. Data was collected through structured knowledge questionnaire. Awareness programme was conducted to increase awareness regarding immunization. Result: 49% samples had good knowledge, 33% had excellent knowledge and 18% had poor knowledge about the immunization. Conclusion: There is a need to increase awareness regarding under five immunization.