OPEC member countries, due to their high dependence on fossil fuels and significant share in greenhouse gas emissions, play a crucial role in global environmental changes, and their trade structure can significantly affect environmental sustainability. In this study, using annual data for eleven OPEC member countries during the period 1995–2022 and employing the CS-ARDL panel cointegration method, the impact of import structure—including two components: diversity and concentration—on the ecological footprint has been examined. The results indicate that increasing import diversity in the long run leads to a rise in the ecological footprint, while import concentration has no significant effect. These findings provide partial support for the “pollution haven” hypothesis, suggesting that the expansion of diverse imports, especially from countries with lower environmental standards, may result in higher pollutant emissions. Furthermore, the results show that technological advancement and the use of renewable energy sources contribute to reducing environmental degradation, whereas industrial growth has a positive effect on the ecological footprint. Therefore, revising trade policies, promoting clean technologies, and expanding the use of renewable energies are essential steps toward reducing the ecological footprint and achieving sustainable development among OPEC member countries.