This study aims to analyze what drives and prevents the purchasing of eco-friendly products across different consumer groups and develops a conceptual model embracing the positive altruistic (care for the environmental consequences of purchasing), positive ego-centric (green self-identity and moral obligation), and negative ego-centric (perceived personal inconvenience of purchasing eco-friendly products) antecedents of eco-friendly product purchase intention and behavior. We empirically validate the conceptual model for green (n = 453) and non-green (n = 473) consumers (i.e., consumers who engage in a set of pro-environmental behaviors for environmental reasons versus consumers who do not engage in these behaviors). Data are analyzed using structural equation modeling and multi-group analysis of the two groups. The results confirm the relevance of the determining factors in the model and show significant differences in eco-friendly product purchasing patterns between green and non-green consumers. Altruistic motives are more important for green than for non-green consumers. Negative ego-centric motives affect the purchase intentions of non-green consumers more than the intentions of green consumers, whereas the impact of negative motives on behavior is stronger for green than for non-green consumers. The first contribution of this paper is the development and testing of a parsimonious model of eco-friendly products purchasing that embraces both positive (altruistic and ego-centric) and negative (ego-centric) antecedents, which have been theoretically suggested in the past but have rarely been empirically tested together. The second contribution of this study is that it develops insight into the specific antecedents of eco-friendly products purchasing for green and non-green consumers to assess potential similarities and differences in eco-friendly products purchasing process, the hypothesized antecedents, their impact on eco-friendly products purchase intention and behavior, and the intention-behavior relation.