Systems for managing municipal solid waste are typically ineffective in developing nations because of governments' deficient financial and administrative frameworks, poor rules, and a lack of suitable infrastructure and human resources. The informal sector plays an essential role in these systems by reprocessing waste into secondary raw materials, reducing collection and disposal costs, and, most importantly, benefiting the environment by avoiding incineration and landfilling. However, their actual contributions remain unknown. The present paper aims to understand the role of informal waste pickers (IWPs) in the waste management system of Guayaquil City and their environmental impact through the calculations of the carbon footprint (CF) avoided due to their aid. The survey design gathered information on their personal profiles, types, and rates of collected recyclables, market conditions, their main barriers, and troubles regarding their formalization. The results of the survey demonstrate that waste picking is mostly a male-driven activity, the average daily mass collected per IWP is 13 kg, the most collected recyclable waste is polyethylene terephthalate, their average monthly income is $179, and the total avoided CF of the entire informal waste picking process is almost 14 thousand tons of CO2 eq yearly. Further, IWPs prefer to operate alone, and only 16% of them would join a cooperative, despite their numerous financial, logistical, and personal challenges