Remanufacturing, long perceived as an environmentally friendly initiative, is supported by a number of governments. Yet, the assumption that remanufacturing is desirable to society has never been systematically investigated. In this paper, we examine the effectiveness and eco-efficiency of remanufacturing in the personal computer and mobile phone industries. We investigate whether remanufacturing substantially reduces the environmental impact, as measured by cumulative energy demand (CED), generated over the life cycles (LCs) of these products, and the size of any reduction. We also examine the relative eco-efficiency of remanufacturing compared with virgin manufacturing for these two products, where eco-efficiency includes both willingness-to-pay (WTP) for the products as well as the energy consumed in producing the products. Our main findings are the following. One, remanufacturing is an effective way to reduce the total energy consumed during the LCs of personal computers and mobile phones, with one notable exception, when the life spans of remanufactured products are substantially shorter than the life spans of their new counterparts. Two, a remanufactured personal computer or mobile phone is not always more eco-efficient than a corresponding new product. Three, the WTP for remanufactured personal computers and mobile phones, and consequently, their eco-efficiencies, are a function of the prices of the correspondent new products at launch and years elapsed between launch and remanufacturing. Four, remanufactured units are sold at a discount relative to the price of new personal computers and mobile phones. Five, on the whole, the market for remanufactured mobile phones is more eco-efficient than the market for new mobile phones. Six, the market for remanufactured computers is more eco-efficient than the market for new computers. Lastly, because the group of remanufactured products is heterogeneous, not all remanufactured units are more eco-efficient than the average new computer and mobile phone. We conclude with a discussion of the impact of our findings on European WEEE and WEEE-like legislation.