An interfacial polymerization reaction was used to coat functional paper with a polyurea film containing N,N-diethyl-3-methylbenzamide (DEET). Preparation of the polyurea film via an interfacial polymerization reaction eliminated the need for microcapsule preparation and coating with a binder, which are processes that are typically required for functional paper preparation. Interfacial polymerization involved the immersion of a sheet of filter paper impregnated with an oil-in-water emulsion of ethylenediamine (EDA) and DEET in a cyclohexane solution of hexamethylene diisocyanate. This fixed the polyurea film that contained the DEET on the paper surface. The amount of DEET fixed on the paper depended on the EDA concentration, and the maximum amount of DEET fixed was 18.65 mg/m(2) for 10 % EDA. The percent content of residual DEET after 72 h on the blank paper was 6.0 %, whereas that for paper prepared using 2.5, 5, and 10 % EDA was 81.4, 73.2, and 57.1 %, respectively. The functional paper prepared in this study could provide for the sustained release of DEET from the paper surface.