Delay in immunization leads to the decreased level of protection against disease. The present study was done at the immunisation clinic at Nellimarla to document age & gender-wise distribution of cases of delayed immunisation and to study common causes of delay. A questionnaire answered by the parents accompanying immunisation delay children was analyzed. Delayed immunisation was observed in 12.8% children. Most common causes showed primary maternal education (41.1%), low socioeconomic status (67.9%), children of higher birth order (69.6%), ignorance (51.8%). Delayed immunization was more during primary immunization.. One should realize that with hesitance or delaying vaccinations, the period that the child is at risk increases.