This species was diagnosed by Andersson (1998) as having thicker-textured elliptic leaves that are shiny above and have tufted domatia, the calyx limb 2.5-5 mm long, medium-sized flowers with the corolla tube 8-12 mm long, and thinner-textured capsules. Andersson compared this species to Cinchona pitayensis, which differs in its longer calyx. Cinchona lancifolia is also similar in general aspect to Cinchona officinalis, with larger flowers and pit domatia on the leaves, and to Cinchona pubescens, with thinner-textured, usually broader leaves.
Cinchona lancifolia is also similar to Cinchona nitida of Peru, which Andersson separated by its leaves that are not shiny above, its calyx limb that is lobed for ca. 1/2 its length, and its larger flowers, with the corolla tube 14-15 mm long. A number of historical specimens from Peru that were identified as Cinchona lancifolia belong to Cinchona nitida as circumscribed by Andersson, in particular Poeppig's collections.