This paper traces plastics streams through the German economy. A material flow simulation model is used to analyze the production of plastics products, their use and residence times in the economy and finally to calculate the present and future amounts of waste. We find that there is an indirect net export of plastics products incorporated in final products which amounts to 3–6% of domestic consumption. Residence times of plastics products range from a few months to 30 years and more, with the weighted average amounting to 14 years. In Germany, total post-consumer plastics waste will rise from 4.6 Mt in 1995 to 6.2–7.2 Mt in 2005 and could easily reach a value in the range of 12–14 Mt in 2025. At the same time, the accumulation of plastics in the economy will increase from about 72 Mt in 1995 to 180 Mt in 2025 in the business-as-usual scenario. The share of waste from long-lived products will continue to grow in the next decades. For polyolefins, PVC and polystyrene in plastics waste, we expect that the total amounts will more than double within the next 25 years. Analyses as presented in this paper can help to establish strategic waste management policies.