Coffee is among the most highly traded agricultural commodities and cultivated across some of Earth’s most biodiverse tropical regions. The conservation literature recognizes coffee farms as potential refuges for biodiversity in landscapes where they have replaced and fragmented natural tropical forests. By contrast, little is known about whether and how coffee impacts native plant communities beyond active farms, as alien species persisting in secondary forests following discontinuation of cultivation and potential invaders into surrounding remnant forests. Here, we explore the literature on coffee in particular and alien plant species in general to identify potential impacts of alien coffee on native plant regeneration. As a prolific, shade-tolerant woody species, alien coffee can theoretically influence native species pollination, dispersal, seed germination, and establishment over prolonged periods, but these effects and consequences for plant community dynamics remain largely untested. Key knowledge gaps include the direction and strength of alien coffee effects on native plant regeneration and how they vary with regeneration stage, native species traits, environmental conditions, coffee species, and forest type (secondary forest vs. invaded remnant). Investigating these gaps can enrich the discourse on coffee and conservation, guide restoration in coffee-occupied forests, and advance the relatively underdeveloped field of shade-tolerant alien species ecology.