Highlights: (1) In Brazil, the addition of pure biodiesel (B100) to diesel oil is mandatory. (2) Waste cooking oil is one of the possible feedstocks for B100. (3) Uncontrolled costs and risks of collection activities make waste cooking oil less competitive. (4) Actions can be implemented to improve the competitiveness of waste cooking oil. Aim: Identify and compare the costs and risks of two modalities of the waste cooking oil reverse chain, known as door-to-door collection, and collection point utilization. Methodology: Data concerning the year 2020 of two waste cooking oil collecting organizations in the municipality of Volta Redonda-RJ were collected by means of interviews and documental research. After the data survey, it was possible to map the stages of the reverse chain of the two companies and compare the results obtained regarding costs and risks in both modalities. The Supply Chain Risk Management - SCRM methodology was used to support data analysis. Finally, actions were proposed to improve results based on a bibliographical survey. Results: Results show that the most risky and costly stage of the reverse chain is that of transportation and collection for both modalities, if compared to the other stages analyzed, identifying a greater need for the implementation of improvement actions. It was also possible to verify that, for some stages, simple control actions can impact the risks and costs identified. Research limitations: The analysis considered only a part of the waste cooking oil reverse chain from a given geographic region and considered only two companies. The other limitation was data collection restricted to the year 2020 and interviews conducted with a non-probabilistic sample. Thus, the results obtained in this study cannot be generalized. Practical Implications: Considering the study performed, it is possible to set up a workflow of the researched organizations so as to assist their managers in the analysis and measurement of their risks and costs. The results can also help waste cooking oil collecting companies in implementing actions that can potentially contribute to improving the performance of their operations. Originality/value: This research contributes to the area of operations, as it raises the main risks and cost ranges per stage of the reverse chains studied, based on the reality of small and medium-sized companies in a region, considering the limitations of financial and human capital resources of organizations operating in the segment. Additionally, the research points out ways for these organizations that have relevant performance from the economic, environmental, and social point of view.