The Industry Council for Electronic Equipment Recycling (ICER) has published estimates of waste generation based on both assumptions and analysis regarding the relationship between the market sales of electrical and electronic equipment (EEE) in a given year and the expected lifetime of products as well as by employing market saturation factors. Further, today, it has become extremely important to reduce the quantity of waste EEE (WEEE). While attempting to improve the recycling rate of WEEE by enhancing the disassembly processes, two issues must be considered simultaneously - economy and safety. In this paper, a Petri net (PN) analysis has been proposed to deal with the disassembly and recycling problems in end-of-life (EOL) WEEE since it can describe the disassembly processes dynamically. By using the PN analysis, the optimal solution between the cost and environmental effectiveness of the disassembly processes is determined. Finally, a case study is illustrated for the disassembly tree model.