The study to assess the planned teaching programme on knowledge febrile seizure among the mothers of under five children in Chennai. One group pre-test post-test design was used and 30 mothers of under five children were participated through non-probability convenient sampling technique. The tool consists of socio-demographical variables and questionnaire was used with 20 items with four point rating scale and the level of knowledge was classified as inadequate knowledge (<50%), moderately adequate knowledge (51-74%) and adequate knowledge (>76%). The results showed that there is a significant difference between pre-test and post-test level of knowledge of febrile seizure among mothers of under five.