A phytochemical study of Asplenium ruta-muraria L. (Aspleniaceae) led to the isolation of a new caffeic acid glycoside, 2-O-caffeoyl-β-D-fructofuranosyl-(2 → 1)-α-D-glucopyranoside and an (α, β)-isomeric pair of 2E-caffeoyl-D-glucopyranoside, together with kaempferol-3-O-β-D-[6-E-caffeoyl-β-D-glucopyranosyl-(1 → 2)glucopyranoside]-7-O-β-D-glucopyranoside, 1-O-caffeoyl glycoside, sucrose, diploptene and β-sitosterol. Their structures were established by means of MS and capillary NMR techniques. Additionally, aromatase inhibitory activity of the extracts and phenolic compounds was evaluated.