Introduction: Despite growing vaccine-preventable infections, immunization campaigns still suffer due to parental resistance. Knowledge and opinion of caregivers about childhood additional vaccines becomes imperative before we stress upon any such promotion under UIP. Objective: To assess knowledge and opinion of caregivers regarding childhood additional vaccines in Agartala, Tripura. Methods: Present study was undertaken during Jul-Dec 2011 in a child clinic at Agartala. Data was collected using pre-designed and pre-tested proforma by interview technique. Information regarding background characteristics of parents, source of information, knowledge and opinion regarding childhood additional vaccines was collected after obtaining written consent. Data analysed using Microsoft Excel and Epi_Info version 6.04. Chi-square test was used and p__ampersandsignlt;0.05 considered statistically significant. Results: Information was gathered from parents of 180 children. Doctors (73.33%) were main source of information followed by television (18.89%). 26.67% and 32.78% parents respectively knew timing and against which diseases additional vaccines are used. 73.89% parents reported vaccination as best way to prevent these diseases. 76.11% opined additional vaccines should be available at govt. hospitals. 46.67% recognized polyvalent vaccines better than monovalent. Numbers of injections (89.29%), cost (21.43%), numbers of visits (16.67%) and less complications (15.48%) were cited for such preference. Financial constrain (46.11%), family disagreement (26.67%), time constrain (20%), fear of complication (18.89%) and non-availability (8.89%) were stated as barriers. Parents__ampersandsignlsquo; education (69.44%) and economic status (41.11%) were stated as family related reason for poor acceptance of additional vaccines. Conclusion: Parents__ampersandsignlsquo; knowledge-gap, opinion and operational issues should be addressed before launching and promoting any childhood additional vaccine campaign.