Background: According to NFHS-5, 2019-21, the country's full immunization coverage stands at 76.1 per cent, which means that one out of every four children is missing out on essential vaccines. However, India has still not reached international standards with respect to full immunization coverage. In Countries such as USA, the percent of children vaccinated by the age 24 months: Diphtheria, Tetanus, Pertussis (4+ doses DTP, DT, or DTaP) is 80.4% and for three doses of Polio vaccine is 92.5%. The present study reflects factors affecting implementation of Routine Immunization services of Infants in a rural area of Uttar Pradesh. The barriers for full immunization coverage have remained unaltered for many years and require careful scrutiny and action Health Visitors (HV), ANMs (Auxiliary Nurse midwife) and AWWs (Anganwadi workers) play a significant role in the implementation of UIP in India, especially in rural areas. However, their role has not received adequate attention and this may be a significant factor in the stagnation of Routine Immunization coverage rates in Empowered Action Group (EAG) states of India. This is a study to understand the barriers of routine immunization of infants, as perceived by the HV, ANMs and AWWs. Methods: A carefully designed Interview schedule was used during August-September 2005, to define the barriers of effective Immunization Health care delivery (IHCD) in block Bisrakh, one of the five blocks of Gautam Buddha Nagar (GBN) district, Uttar Pradesh. Focus Group discussions were held and HV, ANMs and AWWs were interviewed in a group session and observations recorded. Relevant findings were recorded which have a direct impact on IHCD have been presented in the study. Also, inputs for role definition of Accredited Social Health Activist (ASHA) to be positioned in EAG states under the National Rural Health Mission were sought from the ANMs and AWWs. Results: According to RHS-2, the Immunization coverage in the study area was 48%. The most important barriers identified were 1. Lack of adequate training of ANMs and AWWs, as they did not have adequate capacity to handle adverse events following immunization (AEFI) in the community. 2. Lack of clear role definitions of ANMs and AWWs led to confusion during implementation of the UIP. 3. Missed opportunities. 4. Lack of motivation of AWWs 5. Lack of adequate staff 6.Non-availability of A-D syringes 7. Lack of monitoring and supervision at the block level. Conclusions/Interventions: Important interventions to the increase immunization coverage include 1. Re-orientation of the training of the field staff, with emphasis on negotiating skills and communicating with the community regarding AEFIs. 2. Role definition: Defined job responsibilities for each 3. Motivation of AWWs: Try Incentives for good work 4. Alternative arrangements to avoid missed opportunities. 5. Rearrangement/ contractual staff/NGOs/Private practitioners to fill vacancies. 6. Adequate supervision and monitoring by superiors 7. Introduction of A-D syringes may be through user charges, if necessary. 8. ASHA for motivating the community and helping in immunization