The present invention deals with a herbal formulation comprising an extract of Cymbopogon winterianus (Java citronella), Lantana Camara, Nicotiana tabacum, Tagetes erecta, Acacia catechu, Eucalyptus spp., Azadirachta indica.Ocimum kilimandscharicum and Veteveria zizanioides which is effective against mosquito, bacteria, virus and fungi. Effectiveness observed is 98% within 5hrs. Further, the present invention also deals with a method for the preparation of said formulation.