Consumers are increasingly interested to know about the environmental impact of products and, at the same time, they form attitudes after reading online consumer reviews (OCRs). Researchers have investigated the influence of eWOM valence across different product types, however, no research has been conducted on environmentally-framed reviews and products with different perceived environmental impact. Drawing on negativity bias, schema congruity theory, and norm-activation model, we investigate the effects of OCRs carrying environmental messages of different valence, on perceived review usefulness, product attitude and purchase intention in products with low versus high environmental impact. Two factorial experiments (positive versus negative reviews; low versus high environmental impact) were conducted respectively with a sample of 321 Italian and 250 French consumers. Results show a partial support of the moderation of product environmental impact in the relationship between review valence and perceived review usefulness, product attitude, and purchase intention. The findings of the two studies suggest that products perceived to have a high impact on the environment strengthen the impact of positive and negative environmentally-framed reviews about them. The effect of a positive and a negative review is contingent upon the levels of consumers’ environmental concern. Negative reviews of high impact products are more impactful in contexts in which environmental concerns are high, while positive reviews are more significant in contexts in which environmental concerns are low. The perceived usefulness of a negative review about high impact products is a key construct when moral norms are high, impacting attitude and purchase intention negatively.