The efficiency of ethylene vinyl acetate copolymer based controlled release formulations of the molluscicides niclosamide (5,2'-dichloro-4'-nitrosalicylanilide), bayluscide (5,2'-dichloro-4'-nitrosalicylanilide - ethanol amine salt), and trifenmorph (N-tritylmorpholine) was studied against the freshwater snail Indoplanorbis exustus. It could be shown in laboratory bioassays, that the addition of an attractant to the formulations was advantageous in respect to a more selective and more effective control of the snails. The application of such formulations in bioassays with Indoplanorbis exustus in the presence of zebra fish (Brachydanio rerio) caused 100% lethality of the snails without obvious intoxication of the fish and thus gives way to a more environmentally friendly method of controlling snails acting as vectors of trematode diseases.