Purpose: The purpose of this study is to study the various adverse reactions caused post measles and rubella vaccination done during measles rubella (MR) vaccine campaign in India. Materials and Methods: Prospective, observational study was done in a government tertiary care pediatric intensive care unit. Children aged between 9 months to 15 years, who presented with adverse effects (severe enough to warrant admission) within 7 days of MR vaccine administration. Results: Most common presenting complaint was fever (44.8%), followed by vomiting (34.5%), abdominal pain and dizziness (31%). Abnormal body movements were noted in two children (6.8%) on first day and in one child on fifth day of vaccine administration. Two children (6.8%) presented with generalized macular rashes all over the body on 4th day after vaccination. Altered sensorium on same day of vaccine administration was the presenting symptom of one child. All children improved gradually and were discharged after few days with no mortality or long-term morbidity. Investigations were done according to the protocol of the unit; nothing came significant to be reported. Neither of the children had positive blood culture. Conclusion MR vaccination programs are scientifically sound, highly recommended and proven effective globally. Causality assessment of adverse events is still an evolving science, and despite taking all the measures and adopting all the available scientific methods, sometimes it is not possible to incontrovertibly prove the causal association of an event with a vaccine. Much more advancement in this area is needed.